Air horn solenoid valve. Fits horns on M35, M54, M809, M939, etc. Operates on 24 - 28 volts DC. Normally closed valve opens when voltage is applied. P/N MS17981-1, A-A-52525. NSN 5945002401684. Replaces MS17981-1, NSN 5945011700553. Input port is 1/8 inch pipe and output is 1/4 inch pipe.
Includes pipe elbow and tubing fittings on inlet side.
Mating electrical connectors are MS27144-1.