Water Drop Bluetooth Smart Alarm Bag Mobile Phone Kids Pet Keychain Tracker Describe: 1. Color: Black/Green/Red/White/Blue 2. Size: about 5.2 x 3.1x 1.1cm (H X W X D) 3. Devices for IOS or Android smartphones 4. Bluetooth version: Bluetooth 4.0 low energy consumption 5. Working distance: about 98 feet (barrier-free) 6. Suitable for: wallet, car, children, pets, bags, suitcases or other items 7. Battery: button battery (including battery) How to use: Download the App FindElfi (free), put in the battery (we don't provide it) long press the tracker for 3-5 seconds until it beeps, turn on the phone's bluetooth and connect to the tracker. If you always misplace or just want to better keep track of your family, pets and belongings, this handy little tracker is for you! After receiving a bluetooth signal, it will pinpoint the location of your item on the map. Plus, it keeps kids and pets from getting lost in the first place, buzzing and alerting you if you have your phone with you and you and your kids or pets start walking too far.