This 12V 40 Amp Automotive Relay Kit is a reliable solution for controlling high-current accessories in cars, trucks, motorcycles, boats, and vans. Each kit includes 4 complete relay units, model JD1912, pre-wired with color-coded 12 AWG and 16 AWG harness sockets for straightforward installation. The 4-pin SPST (Single Pole Single Throw) design operates automatically at 12 volts with a 40-amp contact current rating, making it well-suited for powering lights, fans, pumps, horns, and other automotive accessories. Pure copper contacts ensure dependable conductivity and long-lasting performance under high-current demands. The compact plug-in design fits securely into tight spaces, while the included screw mounting bracket provides an additional option for a stable, fixed installation. Color-coded wiring takes the guesswork out of connections, helping both professionals and DIY enthusiasts get the job done efficiently. With a wattage of 1.8 watts and a minimum switching voltage of 12 volts, this relay kit delivers consistent, automatic operation across a wide range of 12-volt automotive applications.