This heavy-duty SPST relay harness system is engineered for superior performance in automotive, marine, and industrial applications. Operating at 12V DC with a robust 40A capacity, it features color-coded wires for foolproof installation and maintenance. The sealed design protects internal components while operating reliably in temperatures from -55°F to +158°F. Built with premium silver alloy contacts and boasting a contact resistance of ≤100MΩ, this relay delivers exceptional durability with a mechanical lifespan of 10 million operations and electrical life of 100,000 cycles. The system operates efficiently with just 150mA current draw at 12V, making it ideal for various vehicle electrical systems. With quick response times - 15ms operation and 10ms release - it's perfect for time-critical applications. The compact design includes mounting brackets and pre-wired harness sockets, simplifying installation in trucks, vans, boats, and motorcycles. This relay's versatility and reliability make it an excellent choice for both OEM replacement and custom automotive electrical projects.