This JD1912 automotive relay kit comes complete with pre-wired harness sockets and color-coded wires for hassle-free installation in your vehicle's electrical system. Built to handle 12V/40A power requirements, this 4-Pin SPST relay features a robust design ideal for various automotive applications. The color-labeled wire harness eliminates guesswork during setup, while the pre-assembled sockets ensure secure, reliable connections. Perfect for cars, trucks, vans, motorcycles, and boats, this compact relay delivers consistent performance in demanding environments. The durable black housing protects internal components, while the integrated mounting bracket allows for stable installation. Whether you're working on a new installation or replacing an old relay, this universal kit provides everything needed for a professional-grade electrical connection. The standardized 4-pin configuration makes it compatible with most vehicle systems, offering versatility across different automotive applications.