It is powered by built-in batteries with very low power consumption. The batteries can be used for about one to two years. It is applicable to most DVD navigations with steering control function on the market. The controller is universal, so you don't need to remove the steering wheel controller to operate it. It can support 5 buttons and 10 buttons, two choices to meet the common operation needs of the car. Its super touch, small footprint and side button will not cause misoperation when steering the steering wheel. The built-in arc design is perfectly compatible with a variety of car steering wheels, without adverse effect on the steering wheel cover. Flexibly installed along the steering wheel as you like, the controller is easy to use and helpful to ensure your driving safety. Description: Item Type: Remote Controls Special Features: Easy installation and removal. Item Weight: 0.18 kg Model Name: Controller Key Product Name: Steering Wheel Remote Control Shape: Half Moon