Powered directly from the car battery (12V). It connects to your rearview camera to give you a full view of the back of your vehicle or to the car's DVD player. Technical Specifications: Self-adhesive installation base Screen size: 4.5" Resolution: 480 x 234 pixels Image contrast: 300:1 Voltage: 12V Power: 3W Operating temperature: -10°C to 50°C Net weight: 140g Dimensions: 12 x 7.5 x 1.5 Installation of the screen is recommended to be done by a qualified technician.