A small plastic gadget attached to a keyring, sitting in a car’s cup holder or hidden inside a glove box can leave people wondering what it does. It may have no screen, barely any buttons and no obvious instructions. At first, it looks like an ordinary plastic tag, but in many cases, it’s actually a key finder, a handy device designed to help people locate misplaced belongings.

So, how does it work? You attach it to something you frequently lose, such as your car keys. When they disappear under a cushion, inside a bag or somewhere around the house, you can activate the finder using a button or a connected smartphone app. Depending on the model, it may produce a sound, connect through Bluetooth or show its last known location. Some advanced versions can also use wider tracking networks to help locate lost items.

These gadgets are particularly useful because keys are among the easiest things to misplace. Some people also attach them to handbags, luggage, wallets and other everyday belongings. However, not every small electronic tag is the same. Traditional key finders, Bluetooth trackers and more advanced location devices can look very similar, even though their technology and capabilities are different.

But what if you discover one inside a car and don’t recognize it? Don’t immediately assume it’s a secret tracking device or something suspicious. It could belong to the owner, a previous vehicle owner or someone who has used the car. Check for a brand name, model number or identifying markings to find out exactly what it is. So, have you ever found one of these little gadgets and wondered what it was used for?