Bare metal: 5.5g/piece (not charged) Battery: 3 g / piece Product specification: 60×30×10mm bag specification: 7×12cm Bag full set: 13g / piece (with battery) 10g / piece (without battery) Color: black- and white- green blue colors This Loss Device Is A Product Based On The Latest 5.2 Low-power Technology. Through The Use Of APP Software And Mobile Phones And Other Mobile Devices For Connection, It Can Bundle The Items And Valuables (such As Keys, Handbags, Etc.) 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 Battery Can Work For More Than Half A Year. Suitable For 11 And Above Can Be Used.Android Phones: Android 8.0 And Above, 5.0 And Above. Although The Setting Steps Of Android Phones Of Each Are Different, They Are Almost The Same. First Check The Power Saving Mode Of Your Mobile Phone System, And The Loss Device App To The White List Or Protected Program To - The / Loss Device App From Being Shut Down By The System And Causing False Alarm. At Present, In To Increase The Battery Life Of Mainstream Android Models, The System Has Been Optimized To Varying , 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.