BT tracking helps prevent loss of items. When the phone or other items cannot be found, double-click the button to trigger a sound alert. When an item is misplaced, open the mobile app to locate it and see where it was last detected. Automatic alarm feature alerts you when the phone moves beyond a certain distance from the item, helping prevent loss. Compact size, similar to a coin, making it easy to carry and place in various locations. Two-way search function: double-click the button on the device to make the phone ring, or use the app to make the device sound an alarm for easy retrieval. Product parameters: Product name: Smart object finder Product net weight: 21g Bluetooth version: BT 5.0 Product model: Y02 Compatible systems: iOS/Android Standby time: 6 months Effective range: 15 meters Battery type: CR2032 Color: Black Material: Plastic Package contents: 3 x Smart object finders 1 x Instruction manual (English and Chinese)