This little device can produce a 90 dB sound, which is louder than a typical landline phone ringing. Once within range, you can open the app and select the tag you want to start ringing. This really helps you find your keys quickly.
There's a small "e" button on the tag, and double tapping it will use the Bluetooth connection to make your phone ring. Your phone will ring even if it's on silent mode.
The range effectively is only around 90 feet (30m). If you have a general idea where you left your keys, this should be enough, however outside of that range this device probably won't help you.
Because the Tile uses a Bluetooth connection, it can't tell you which direction your keys are. Instead, it displays 8 bars, and the less bars that are displayed, the closer you are. It will take a bit more time to hunt your keys down like this, but there is also an alarm you can sound once you're within range to help speed the process along.
These tiles are very useful for different keychains, and if you have kids that have their own keys you can be limited by the number of tiles you can have tied to an account.
The Bluetooth connection between the Protag and your phone is about as reliable as you can expect. It's range is about 75 feet consistently, which makes this one of the best key trackers so far.
If you move out of range of your Protag Duet, it will alert your phone through a notification. This helps you to remember your keys before you lose them.
At 80dB, this alarm is quieter than the rated value of other key finders. This noise level reduces down to 50dB when measured 5 feet away, which is just a bit quieter than an average conversation
If your keys are lost outside of your range, anybode else with the Protag app can help you find your keys. Their app will notify you automatically (without them knowing), and update you with your keys' current position. This feature requires many Protag users to work effectively, but it increases the chances of you finding your keys even if only by a slim margin.
The advertised 200 foot connection seems like a massive exaggeration. In real-world tests, it would lose connection around 60 feet and wouldn't pick up the connection again until it was 20-30 feet away. This very short range isn't much help in finding your keys.
The battery life is rated around 6 months, and you can replace the battery yourself fairly easily. It uses CR2025 batteries which sell for around $1 each, or considerably less if you buy bulk packs.
While there are no buttons on the Chipolo, if you shake it hard enough it will make your phone ring for 10 seconds (if its within range). This feature is great if you lose your phone, but have your keys on you.