The device works on OBD2 gasoline cars (1998 and newer cars in the USA), and EOBD cars (cars from Europe, gasoline cars from 2001). Bluetooth connection, no Batteries, Cables, or Switches. - Wireless (Bluetooth) 5 ~ 10 meters. Notice: 1. NOT for iOS For iPhone & iPad, please choose "Wi-Fi for iOS and Android". 2. NOT for Diesel vehicles. 3. For your vehicle to be OBD II compliant it must have a 16-pin DLC (Data Link Connector) under the dash and the Vehicle Emission Control Information Label must state that the vehicle is OBD II compliant. Suitable for system: mainly used with Android system phones, also supports Symbian system phones, Windows system PCs and laptops. Compatible App: Recommended Apps are Torque Pro, Torque Lite (free), OBD Car Doctor (free), etc. on Google Play. Work with Android cellphone and tablet. Or There are various Apps and installation instructions provided on the CD. But Partial Apps need to be charged. You can run the CD to select the appropriate App. How to use: Plug the device in your car's OBD2 port, start the car, enable Bluetooth on your Android phone or tablet, search for "OBDII" and pair with it (pin 1234), run the downloaded App with simple settings and wait until it connects your car's ECU successfully. If you use the same OBD on 2 or more cars, you need to disconnect Bluetooth and close App when finish testing one car, and re-match the Bluetooth when you insert the OBD into another car.