It is powered by built-in batteries with ultra-low power consumption. The batteries can last for approximately one to two years. This controller is compatible with most DVD navigation systems that have steering wheel control functionality on the market. The controller is universal and does not require removal of the steering wheel cover for installation. It supports both 5-button and 10-button configurations to meet common in-car operation needs. The touch-design features compact size and side-mounted buttons to prevent accidental activation while steering. The integrated arc design fits seamlessly with various car steering wheels and does not interfere with steering wheel covers. The controller can be flexibly installed on the steering wheel as desired, making it easy to use and helping to maintain driving safety.Item Type: Remote Controls Features: Easy installation and removal Item Weight: 0.18 kg Model Name: Controller Key Product Name: Steering Wheel Remote Control Shape: Half Moon Controller Key Dimensions (L x W x H): approximately 10 x 4.4 x 3.5 cm / 3.9 x 1.7 x 1.4 inches Receiver Box Dimensions (L x W x H): approximately 4.3 x 3.7 x 1 cm / 1.7 x 1.45 x 0.45 inches Material: ABS Color: Black Package Contents: 2 x Controller Key (with built-in button battery) 1 x Receiver Box 1 x Wire Harness 1 Set x Screws 1 x Instruction Manual Note: Light and display differences may cause slight variations in the color of the item compared to the picture. Measurement tolerance is +/- 1-3 cm. Only the items listed above are included.