About the size of a quarter! Only 0.16 Inches (4.1mm) thin . That means you can stick it anywhere. Stick them to any device, person or animal, and find them with your Smart Phone. An Amazing App The Radar Screen displays all your devices within range. You can tap the Sticker on the radar screen and decide if you would like it to Buzz, Flash the lights or do both. Of course, because we don't really