The Bluetooth disconnection will automatically alarm, and the APP will record the location when the connection is disconnected. Open the APP and click the alarm, and find the item according to the ringing of the anti-lost device. Two-way search to prevent loss Double-click the button of the anti-lost device, and the phone will ring. Bluetooth connection Effective distance of 15 meters Bluetooth 5.0 connection, the distance will be farther without interference. Alarm reminder for lost items, easy to find. Product name: anti-lost device Bluetooth version: Bluetooth 5.2 Use system: IOS/Android Effective distance: 15 meters Battery model: CR2032 Product size: 37 x 37 x 8mm Material: ABS color: Green/Blue/Black/Pink/White<br><br>Package Contents: 1 x Locator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.