Simtek Duo
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It may look like a miniature alien spaceship, but the Simtek Duo does something much simpler: it sends you an alert when it sees the light. As in literal, visible light and/or motion. What’s the point? Put it inside of a safe, a drawer, a suitcase, a closet, a storage unit, etc., and receive an alert if it’s opened.

The Duo is on Indiegogo right now. Yes, crowdfunding. I know a lot of us don’t much like that method of raising capitol, but the Duo is way beyond pie-in-the-sky napkin sketch stage. I received the loaner prototype seen above back in October, and it did exactly what it’s supposed to.

I took it out of the box, plugged one of the cellular antennas into it, installed the battery (it’ll run for a year on a CR123, or use a rechargeable and plug the unit into a USB charger), and . . .

Synced it up with my phone. Seen above, the Duo’s app now just has you scan the QR code and you’re done. With my prototype I had to send a text message to the serial number on the bottom of the unit and it did the rest. It’s easy either way (and the serial number trick is still a back-up on the production units).

I then threw it in my closet on top of my safe. As you saw in this review, my Snap Safe was assembled inside of my office closet. Nobody opens that closet but me, so I figured I’d prefer an alert as soon as the closet door is opened rather than have it wait for the safe door to be breached.

Many users will put the Duo inside of their safe instead, which might make more sense if your safe is exposed in the garage or elsewhere rather than in a dark room by itself. But there’s definitely an advantage to being warned earlier, rather than later, of any trespass.

I then opened and closed the closet door, both with the office lights on and with the lights off. It works. I received a text message every time.

Over the course of the next couple months the Duo never failed me. If I opened that closet door, I got a text. Sometimes I’d get a couple texts if the unit recognized the light and then caught my movement, which was a little annoying. Though well worth the additional peace of mind when I was away from home.

When I was testing the prototype it was a text message-only affair, but Simtek now has an app. The Duo still works via cellular network to provide functionality when WiFi would fail (power outage, internet outages, etc.), but text message notification is no longer the only option. App-based notifications give you more control and allow notifications from one unit to hit multiple devices.

To summarize…open up your Duo and scan the code on the bottom.

Put it in your gun safe…

Your suitcase…

Your storage locker…

Simtek Duo

Your nightstand. Your vehicle’s trunk. A vacation home. Etc. etc. etc.. Receive notifications if the Duo senses light or motion (visible light sensor plus passive infrared motion sensor = “Duo”), which can be put to use in dozens of cool ways unrelated to firearms storage.

New versions will also have location tracking functionality. So, should it be inside your safe and the entire safe is stolen (P.S., bolt your safe down), you’ll be able to track the location of the unit regardless of whether the safe has been opened yet.

I’m guessing Simtek is named after its founder, Mr. Simpson, but it could just as easily stand for Simple Tech. The Duo provides security and meaningful peace of mind in a simple, functional way.

It’s nearly instant to set up and does exactly what it’s designed to do. And it’ll do it from anywhere on earth with GSM cellular service to anywhere on earth with GSM cellular service.

Better yet, the Duo is security and safety that doesn’t slow you down. It’s one of the very rare solutions in this vein that even the most vehemently anti-gun and pro-gun people can get behind. I returned my prototype loaner but will be picking up a production unit, as I enjoyed the peace of mind it gave me while I was away from home.

Specifications: Simtek Duo Portable Security Sensor

Dimensions: 1.48″ x 3.66″ x 3.26′
Weight: 4.3 oz
Material: ABS plastic
Battery Life: up to 1 year
Sensors: visible light and passive infrared motion
Sensitivity: any visible light or 15′ by 15′ motion detection range
Connectivity: cellular (GSM)
Battery Type: rechargeable lithium ion CR123a
Warranty: 1 year limited with free tech support
MSRP: (a new version, the StealthALERT is available HERE)
Estimated delivery date is October 2018

Ratings (out of five stars):

Overall * * * *
The Duo does exactly what it says it will and it’s simple as can be. I think $400 seems awfully rich, though. $199 is more like it, and I hope to see them hit a high enough production volume to make $199 (or less!) a permanent price. The Duo provides a service that many of us can take advantage of, but its cost is going to be a barrier for many.


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    • Traveling is one of the top reasons I use Duo. I take it with me abroad or any trip really, and stick it in the hotel safe with my passport and money (I don’t trust the hotel staff with the safes). If they don’t have a safe, I just throw Duo in my luggage and close it. It won’t give me a false alarm if they move my luggage around, only if they physically open the luggage. Founder here – feel free to ask any questions you all might have! Great write-up.

        • Hi Dave,

          If you pre-order now, you will have location tracking.

          The unit we sent Jeremy back in October didn’t have that feature yet, all new Duo’s that we will ship will have that feature.

          The pre order with the Lifetime Unlimited plan is the best deal we have.

          We are excited to get feedback from early customers can’t wait to enhance security for everyone.

          – Brady, Founder

      • Thank you for your last answer to my question.Now, how do we pre-order? When ordering I will need your business EMAIL,business address,and business phone number. The URL will not satisfy requirement for business EMAIL. You heard the old saying ” A picture is worth 1000 words ” ? Please explain to me that if Jeremy S was given the device in Oct 2017 to try out then why does the second picture he post in article of phone have phone alerts with dates of January and February 2017? The second picture he post of phone alerts is of alerts Oct 2017. To say I am confused that he has picture of phone alerts months before he received Simtec Duo Portable Security Sensor for testing is an understatement. Product is something I will buy if you can answer my questions and concerns.

        • David

          Those app images from February are for press, those purple app images weren’t taken by Jeremy. You can see more of them at

          The app is on the iPhone App Store already – feel free to download to check it out. Android will be available before we ship.

          If you’re interested you can pre order on Indiegogo.

          We are a California company you can look up in the database and email me, the founder [email protected] if you have any questions. Thanks for the comment!

      • I’m interested in getting one of these. Have you considered an option for pay-as-you-go cell plans for a lower initial price?

        • Every Duo comes with two free months of data, then just $3.99 / month.

          You can pick the $139 single Duo and use the monthly plan.

          If you like, you can use your own other simcard and don’t use ours. But, the cheapest pay as you go plans are at least $10-$20 per month from carriers in the USA and aren’t as good because Duo connects automatically to the best signal network anywhere in the world. Take it to Texas then Toronto and you don’t have to change or do anything.

          We give people many options and want them to have flexibility.

        • I edited my post to reflect the info you posted below but not sure it took. I see there;s an option for 139 for a unit with two months of service plus 3.99 a month thereafter.

        • No problem, always good to give people information publicly.

          We’d be glad to have you onboard and get your feedback. We plan to treat early customers wel – we have found them to be the best at giving feedback and being invested in the product and company. Thanks for your interest.

      • I’m curious why you made the design decision to not include a camera and snap a pic to send with the warning? Technical problem, or just added expense without (a perception of) significant added benefit?

        • Very good question.

          The answer is both technical and not significant value added. Here’s why:

          1 – Not a ton of added value, because 99% of the time it’s just going to be you grabbing your things and is overkill. More importantly, if Duo is in a safe, typically there is very little light and it’s only going to capture your hand visually. And lastly, most people choose to stealthily place their duo in the safe or wherever they are monitoring – likely not to capture the suspect’s face and anything meaningful.

          2 – Technical limitations. Adding a camera that snaps a low-res pic everytime and transmits via SMS to the user would significantly reduce battery life, and would also increase the time to send the alert to you.

          What we decided instead, which we felt was a better option:

          – Integration with common surveillance, so you can see footage around your house / around your Duo when an alert goes off, right within the Simtek app. We’ll allow you to hook up your Nest Dropcam to Duo, so that when Duo alerts you, you’ll immediately have access to the previous 30 seconds and following 30 seconds of an alert. Here’s an example: You have Duo in your closet safe, and a Nest Dropcam in the room facing the closet area. You of course turn off alerts on the Nest Dropcam, because it’s a high traffic area and you don’t want false alarms. Someone breaks into your closet safe, and within the SMS alert you are able to see the footage from your Nest Dropcam surveillance camera in the past minute surrounding the alert. This way, you get the full picture of what’s happening, instead of just a quick 1 second snapshot within the safe that likely wouldn’t net anything meaningful.

          We have many cool new features and integrations that we’re planning. We’re just getting started.

          Thank you for your question – I hope others can benefit from it as well.

      • Why would it not sense movement if your suitcase was moved? Can you select for just one, movement or light, or select for both? Or does it only sense “visible movement” and not felt movement?

        • Thanks for the comment. Correct, it will only sense “visible movement”.

          Duo won’t send an alert if the suitcase is moved because it doesn’t use an acceleremeter for detection – it uses passive infrared detection. This means Duo needs to see some human (or animal) heat motion.

          Bumping around in the case has no human or animal that it detects, just inanimate object which doesn’t set it off. You could have it in your car’s glovebox and going over tons of bumps and thrashing about – would never go off, until that glovebox is opened and it detects either light or human motion.

          Check out this Facebook Live we did recently demo-ing the product and talking about some of those questions.

    • You can use your own simcard if you like, but it’s not recommended – we have a special one that connects to thousands of networks around the globe automatically based on which has the best signal where you are. We give two months data free.

      We are currently selling Lifetime Unlimited dataplans with the Duo for $199.

      That’s a one-time payment for Lifetime of Unlimited use and data – never paying a monthly fee.

  1. Thanks for the question! You can purchase a Lifetime Unlimited dataplan and the Duo sensor for just $199 altogether. Or, it’s $139 with two months of free data, then just $3.99 / month.

    Duo uses a special global simcard that works in 200 countries and connects automatically to the best networks wherever you are in the world. In the USA it connects to either AT&T or T-Mobile depending on which one has the best signal.

    Technically, you can swap out your own GSM simcard if you like.

    We chose cellular > WIFI or Bluetooth because we found it much more reliable, less hackable, and able to pass the transmission through most safes. Additionally, it works out in the field – say at a storage unit, or a vacation house, or at the car etc. It’s been tested in basement armories in police stations and worked fine – wifi and bluetooth have severely limited range and were not as performant.

    TLDR: you need one, but you get it from us with the device and don’t have to worry about setting anything up. And you can have as many people as you want receiving alerts.

  2. Neat from the perspective of holistic security. I think it’s something that needs to hit the main stream, in reality it’s pretty darn simple. Really too simple for a $200 price tag once mass production hits.

  3. You can pick one up for $139 – that price includes Unlimited data usage for Life.

    It’s on the high side because we believe that the value it provides is worth every penny once you start using it.

    There’s actually no device comparable (one year battery life on a cellular modem. An iphone is good for about 24hours at best).

    We also have location tracking, and plan to integrate with common surveillance systems like Nest and Arlo, so when you get an alert you can also see all footage. The tech inside and supporting Duo is best in class. And we designed it to be super simple, but super reliable!

    In the future, we’ll continue to unlock future value for people through “over the air” updates, and give people even more functionality. So we’re just getting started.

    Thank you for the feedback!

  4. Does the app support multiple units?

    If, say, I want one in my safe and one in my nightstand, will they both be able to alert to the same device?

    Conversely, can I have a unit alert to multiple phones?

    • Yes and yes.

      Alerts come in via SMS text, so you can have as many units as you like alert one number. You could have five units all around the house or property, customize the alert messages and have them all alert one number. None of this setup requires any heavy lifting – just a couple taps on the app and you’re done.

      Similarly, each unit can alert multiple people – there’s no limit.

  5. I really like the idea of having a safe in a closet, and that device signaling if the closet is opened.

    More time for you to call the cops and catch the bastards as they are trying to get into your safe.

    Best luck with this one, Brady…

  6. How secure is the software it uses? Can it be hacked allowing a thief to know that I’m getting a firearm out of a safe? Or does the police have access to it, in the event that someone gets swatted and the police come in guns blazing if they detect the person inside opening their gun safe, when a citizen is merely trying to defend himself?
    Call me skeptical but I’m weary of bringing in any smart device in my home to the point that I’m looking at going back to a flip phone.
    (If there’s trout in the milk you have to look)

    • Great questions.

      Duo is highly secure (much more secure than bluetooth or wifi) for a few reasons. And police cannot have access to it.

      1) It’s uni-directional communication only, meaning Duo sends outgoing alerts, and cannot receive any incoming commands or texts to it.

      2) It uses traditional cell networks like AT&T and T-MOBILE which have encrypted networks. So, it’s just like your flip phone in that regard. It’s easier to hack a smartphone than it is to hack a carrier network or data transmission across their services.

      3) And this is probably the most important one: No one would ever know what you’re monitoring and getting alerts to. For all we know, you have Duo in your cookie jar or cigar box or monitoring the closet with the Christmas toys. Since Duo simply sends a text alert (with whatever message you customize) and does not have any visual imagery, no one would ever know what you’re monitoring. So, the data would be totally meaningless to them without additional context.

      TLDR: Duo is highly secure and uses regular cellular networks which have several layers of encryption. Additionally, even if someone were to hack the transmissions they would only see a generic alert, and would have zero idea what you’re actually monitoring. So really it’s too basic for them to do anything nefarious. Hope that helps!

    • Thank you for the comment!

      I’ll outline a few reasons why the Elertus is a poor option, and how Duo is engineered from the ground up to be more reliable, flexible and highly performant.

      1) They use Wifi, which is easily hacked and defeated. Simply unplug the wifi router or cut the power and it’s done. Someone change the password recently and you didn’t update the elertus and it’s broken. You can’t easily defeat Duo and it’s highly secure since it sends SMS over carrier networks. Duo uses it’s own network and it’s own power.

      2) WIFI has limited range, even inside a house. Duo uses a GSM cellular modem, making it global, and doesn’t need any setup wherever you take it. Take Duo from your basement to your cabin to your trip abroad, never worry about connecting to any WIFI or external power, it just works automatically. WIFI also doesn’t transmit through low-signal environments as well as a cellular (when you have almost no cell signal, you can almost always push through an SMS text).

      3) Complicated, lengthy setup. Duo sets up in seconds with a QR code. see just how quick here.

      4) Unreliable – when the Internet goes out, you get a false alarm saying your Liberty Safe device lost connection. Duo conversely only connects to the network during trigger events. This means you’re never going to get false alarms with Duo.

      5) Liberty does not work with modern routers. Their product is 6 years old at this point (licensed and developed in 2012 from another company, they did not engineer it) and does not work with modern WIFI routers, significantly limiting who can buy it.

      Duo is a different product, we use different sensors and took a different approach.

      Two other really unique things about Duo, which no one else has:

      – Location Tracking (cellular triangulation)
      – Future surveillance camera integration (Nest Dropcam, Arlo etc.)

      Check out our channel to see more about how Duo works, and why it’s unique.

  7. That is why on our last road trip we got a brand new loaner of 2018 Mitsubishi Outlander and I insisted that the kids left their electronics at home.


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