The main function of this product is power on, it can be used alone, it can also be connected to the control in use, but this product does not include an additional control relay, and if the controller is connected, it is mainly used in a dual battery. Features: The surface is made of good quality nylon material, stable structure and long working time. Constructed in pure copper coil, with high conductivity. With a fixed frame that is stable during operation. Silver material, arc extinguishing resistance, low resistance and convenient installation. Help extend battery life. Specifications:Rated Power: 12v, 24v (Optional)Rated Current: 500A Coil Weight: 7.2W Factor: BlackMaterial: MetalPackage Size: 90*82*60mm/3.5*3.2*2.4inPackage Weight: 257g/9.1ouncePacking List:1*Relay