Crystal Bluetooth 4.0 Anti-lost Device Smart Reminder Anti-lost Device $ 5.01 Compatible platforms; iOS, ANDROID Battery capacity; 200 mAh Interface; Bluetooth Applicable objects; smartphone users Applicable platform; fully compatible Applicable people; universal How to wear; clip-on Wireless distance; 25 meters Product weight; 24g Product size; 41 * 41 * 8MM Additional features; tracking / alarm Material: Plastic