This Waterproof Automotive Relay is a reliable 12V 40A 4-pin relay designed for a wide range of automotive electrical applications, including lighting, horns, fans, and general vehicle electrical systems. Built with high-grade copper terminals and a matching relay socket, it delivers stable conductivity and dependable performance in demanding conditions. The waterproof design shields the relay from moisture, dust, and harsh environmental exposure, making it well-suited for under-hood installations. The compact black housing measures approximately 1.1 x 1.2 x 1 inch, and the included wiring harness socket extends 5.2 inches for convenient hookup. Color-coded wiring — black, red, and blue — along with clear terminal markings, makes polarity identification straightforward and simplifies installation. The universal 4-pin configuration is compatible with most standard vehicle relay sockets, ensuring a hassle-free fit across a broad range of makes and models. Available as a set of two, these relays are a practical addition to any automotive electrical project or repair.