Installed in the car battery Real-time Monitoring Through Mobile Phone APP (Free app for both iOS & Android). Receive notification of battery conditions when enter Bluetooth range. Show voltage & charge info. when user is close to the vehicle,no need open app. Automatic synchronization when enter Bluetooth range. Check starting(cranking) system when each time engine started Check starting voltage each hundredth of a second when engine is starting.<br><br>Support: All 12V Car Battery Available: Android 4.3 and Later IOS: IOS 7.1 and Later For iPhone: For 4s and Later For iPad: For iPad 3 and Later Language: English Connection method: Bluetooth Colour: black Material: ABS Size: 17x13x2CM<br><br>Package Contents: 1 * Battery tester<br><br>Only the above package content, other products are not included. Note: Light shooting 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.