How to Use: 1. Ensure the direction of water flow through the cooling system 2. Connect the hot coolant hoses to the inlet and outlet of the heater. 3. Wire the heater switch to your vehicle's electrical system The red wire of the switch is connected to the positive pole of the power supply and heater. The blue wire of the switch is connected to the negative pole of the heater. The black wire is connected to the negative pole of the power supply. Specification: Item Type: Car Heater Material: Copper, Iron Characteristic: Single Sided Four Hole Type Color: Gray Voltage: 12V Power: 8A Applicable Models: Can be installed in fuel vehicles with water tank heat dissipation Package List: 1 x Car Heater4 x Hose 6 x Fixed Buckle 4 x Connecting Pipe 1 x Switch 1 x Wrench