The ProLink SPDT40M features a hermetically sealed plastic housing with a removable metal mounting tab. ProLink relays feature high-quality copper coil windings, high-current contacts and are manufactured under strict ISO standards. The SPDT40M also meets a minimum rating of 40 Amps on the normally open contact leg (87a), and 30 Amps on the normally closed contact leg (87). With a higher current capability than the venerable industry standard Bosch relay, the SPDT40M is the best choice for your single-pole double-throw relay needs!