1. This loss device is a product based on the latest Bluetooth 4.0 low-power technology. Through the use of APP software and mobile phones and other mobile devices for Bluetooth connection, it can bundle the items and valuables (such as keys, handbags, etc.) that users are easy to lose together, and realize the functions of loss reminder, two-way search, remote control photography, recording and so on (such as party photo, hand bag, etc.) Self portraits, etc.). 2. The effective use distance of the device can reach 25 meters in a wide range. The button battery CR2032 can be easily purchased in Major- supermarkets. The brand original battery can work for more than half a year. 3. Appl e phone: Phone 11 and above can be used.Android Phones: Android 8.0 and above, Bluetooth 4.0 and above. 4. At present, in order to increase the battery life of mainstream Android models, the system has been optimized to varying degrees, and will automatically clean up the app running in the background. When using the loss device, the app needs to be set and protected in the system to realize normal operation. 5. Although the setting steps of Android phones of each brand are different, they are almost the same. First check the power saving mode of your mobile phone system, and add the loss device app to the white list or protected program to preven t the / loss device app from being shut down by the system and causing false alarm. Product parameters: Bare metal: 5.5g/piece (not charged) Battery: 3 g / piece Product specification: 42 * 40 * 10mm bag specification: 7 * 12cm Bag full set: Hos t + Battery + hardware BUCKLE + PE bag Bag full set: 13g / piece (with battery) 10g / piece (without battery) Color: Black pink green gray sky blue dark blue total 8 colors Contain: 1 PC square loss preventer 1 PC Hardware BUCKLE 1 PC battery