Duet by Protag

When we first started testing key finders two years ago, Duet by Protag offered the best mix of features and performance in a wafer-thin 1.1 x 1.1 x 0.2-inch case. Alas, the Duet has stood still while other key finders — specifically the Tile Mate and TrackR Bravo, but also the Chipolo Plus — have made tweaks and improvements. We had some success using the Duet in the past, but it's hard to ignore the advances rival products have made since our initial review.

How Duet Works

Duet's app is available for both Android and iOS. In the app there are a couple different alert options. The most effective is the Buzz feature, which causes the Duet to emit an audible, if not exactly piercing, beep for 15 seconds. A second feature, Radar, uses bars and buzzing to indicate how close a lost Duet is to your mobile device.

A geofencing feature can send alerts to your phone whenever you stroll out of range. A Wi-Fi Zone feature keeps those alerts from sounding when both your Duet and your phone are connected to the same Wi-Fi network. Sadly, there doesn't seem to be a way to disable those alerts when your Duet is in a secured location — say, inside a backpack that you have in the trunk of your locked car as you walk away to run errands — other than dismissing the alerts your phone sends to you once you walk out of range.

You can also see a map of where your Duet was last recorded. If someone else with a Duet walks by, that person's app will ping the map to alert you of its location. We like the idea of the crowd-sourced locator feature, but it does require lots of other people to also own a Duet.

Duet doesn't just let you track your valuables; it also makes sure your phone isn't out of reach. Press a button on the Duet device, and your phone will start buzzing and beeping — assuming it's in range.

How Duet Performs

When we tested the Duet, it offered the most consistent performance of any proximity sensor. Other sensors have caught up in reliability, though the Duet's range of 70 to 80 feet remains among the best we've seen. We had less success hearing the alarm, which was fairly faint, even indoors. When I lost contact with the Duet, I usually had to walk 20 feet toward the device to re-establish contact.

Credit: Jeremy Lips / Tom's GuideCredit: Jeremy Lips / Tom's GuideWhen we tested the volume using our decibel meter, we couldn't register even 50 dB at 5 feet away. That's on a par with the category average. At 1 inch, however, we recorded 79 dB, which is louder than the company's own claims. 

Battery life for the Duet is about six months, but Protag includes one replaceable CR2016 battery, so you can expect to get a year's worth of battery life out of the device before you pay up for new batteries. While it is the second-softest alarm we tested, when you consider the two-way tracking feature and consistent range, this is the most reliable choice if you're looking for a wireless key finder.

Bottom Line

It's worth noting that our experience with the Duet doesn't match that of some Amazon customers, who've criticized the device's reliability. With other trackers catching up to and even surpassing the Duet, you've got plenty of other devices with better reputations to consider. We hope to one day see if the Duet can come up with an update that helps it regain its place near the top of the key finder pile.


Range: 70 to 80 feet on average; Longest distance 81 feet
Battery Type: Replaceable CR2016 battery
Loudness claimed (dB): 75
Compatibility: Android, iOS

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  • Johnbachman
    I am surprised there is mention of the Cube. That is the brand that I hear so much about. How does it stack up with the other key tracker devices. Was it in the test and just didn't rate?
  • mwamac
    This device was not that good. The tile and phone could be right next to each other and not work. It kept losing it's bluetooth connection. Went ahead and returned the tile, if no bluetooth connection, it is useless for finding anything.
  • McMhouse
    I'm looking for a key finder now, and this is the best, most current article I could find. It's a very well-written, in-depth, and comprehensive article. Great work! That said, I agree that the omission of a review of Lapa is a mistake. Would you please add them to your research?

    (I also looked into Pixie, but I don't think there's a need to review them in this article.)
  • loaf__
    I had a TrackR. It is now in the bin. Didn't work and when I dared complain on the Facebook page they deleted my comment and blocked me. Avoid.
  • CRM123
    The Trackr is the worste device. It is barely audible. The bluetooth range is terrible. The bluetooth connection fails all the time and their own tech support recommends that you have to restart the Trackr app on your phone several times per day in order for it to work. Who would do this. Trackr is a useless implementation of a good concept. BUY TILE.
  • larry1976
    Hmmmm... If I buy one Tile at $25 and have to replace it for $12 that's $37 spent in just one year. Not to mention if it goes before 11 months I'm out a beacon until I get a new one. Sure they might let me recycle early but I'm still without a Tile until the replacement gets there.

    If I buy any other beacon I'm still spending $25 average and If I replace the batteries once every 4-6 months I'm out $0.25 per battery (CR2032) and I'm never without my beacon.

    Also not having the Geofence is an even bigger set back. I don't want to have to go looking for something once I've lost it. The whole point is to not lose it and having the alert is huge. Walk away and your phone alerts you're out of range... OH! let me go back and get my item now.

    So the number one beacon costs more because you can't replace the battery and won't alert you before you leave an item behind. But it looks cool, beeps, improved their range from the first generation and you can beep your phone but only if you actually have it.

    That doesn't seem right.
  • Bill62
    In my experience, the tile has been a dismal failure. I tried an experiment and spent a few months with Bluetooth disabled on my phone to see if my tile locations would be updated by other tile users. Absolutely not one update within a two month period. When I bought my tiles, I did so with the understanding that when the battery died I needed to buy a new tile. I had no problem with that notion until the tile people quit reporting my tile location after one year even though my tile had very little use and still had battery life. They showed up green on my phone app, proving they still had battery life, but we're useless because the folks at Tile decided I needed to buy new tiles even though I had functioning tiles.
    This is my first post on this topic, but I have a complete documentation of my experience, including communication with Tile support.
    Not impressive.
  • pixienightfae
    I have tried two item finders - Tile and ProTag Duet.

    With Tile, I was actually a Kickstarter contributor, and it was a pretty abysmal experience. They kept changing the date the tags would be sent out, butting right up to when we were supposed to receive them. Which seems okay, but then I couldn't use it with my phone because I had an Android (which not realizing that was my bad)... luckily, i have a husband with an iPhone. Eventually I stopped using it because they added too much bulk to my wallet. We went back to them and then it said we'd have to replace them - which it wouldn't let me do when we transferred two tiles to my own account (because when we started using them again there WAS an Android app). I hear they are developing a thin tracker now (perfect for wallets), so I might recommend it to my husband - who seems pretty happy with them.

    With Duet, getting them was even WORSE. I was really looking forward to because able to have a credit thick tracker and the battery just didn't last NEARLY as long as it indicated it would. mostly because it would make the alarm go off on my phone if I didn't have the app open. Seriously. It was horrible. Then I broke the back of the other tracker when I went to replace the battery in it. So I called it on that one.

    I might be trying the pebblebee or the Chipolo next because really - it can't be WORSE than either one of those. If Pixies had an Android app, I'd be down to try them also.
  • MrRickV
    I have tried and tried Tile, and the results were the same - Overated and not worth the annual fees that you must pay not once but two of three times a year. Two purchases, two models, and two returns. Wait for as better product.
  • Neon Thomas
    Does it really work? Are there any free kinds?
  • roncro
    I don't see a definition of Geo Fence, but it sounds the same as Separation Alert which I understand Tile has. So I don't understand your report that Tile has no Geo Fence. Well, maybe that feature wasn't there a year ago when you posted this. Can you explain?

    I don't understand Mrrickv's statement he must pay annual fees two or three times a year. Can he please explain.
  • HowzBuy
    I am surprised that although you can't replace battery of Tile it is best seller on Amazon !! Battery is the only issue of Tile which is making me confused about !!
  • 1ps930
    RONCRO Dec 5, 2016, 5:30 PM

    I don't understand Mrrickv's statement he must pay annual fees two or three times a year. Can he please

    Tile has non replaceable battery so your basically on a contract for life by rebuying each year
  • 1ps930
    Amazon best seller should only be a guide to point you in a direction. I see a lot of junk people buy on Amazon that are best sellers. why? because of price and the lack of information. Tile users will pay every year like a contract to keep it going. ie..$25 purchase $12.00 at the end of year to replace. 1st year cost 37.00 end of next year 12.00 again this is provided you are buying the CHEAP Tile and no price increases have occurred.
    In 2 years you've spent $49.00 for an obviously poorly made disposable device. If it wasn't poorly made you wouldn't need a new one every year
  • KlasL

    When will you review the updated chipopo original?

    Your reviews seem to be the best, so I wait to purchase a key tracker until you have reviewed it. Replaceable batteries is crucial to me.
  • Kevin_235
    Tile slim is crap! The mate is ok when you lose your keys or phone but that's the limit.
  • rhodo93
    I love my Tile (original model), but the non-replaceable battery is completely unacceptable. Every year I have to replace the entire unit. They offer a 30% discount on ONE renewal Tile for a total price of ~$12 (plus $3 shipping), but if you use more than one, you're paying full price for the rest of them. And I can't even imaging the e-waste. The next time it "expires," I'm moving to another device with a replaceable battery.
  • checkcheck16
    For the duet: does the alert it send you when you leave it in the locked trunk scenario just beep once or do have to keep dismissing until you are back? Also, can I opt out of the mapped network option or is that forced.
  • John_658
    Why are you recommending the Trackr Bravo? This is a terrible product. Battery life is less than 4 weeks (not 1 year as advertised) and range is less than 10 feet (not 100ft). Two major flaws that make this product impractical to use.