CALISTOUS Metal Car Train Truck Air Horn Electric Solenoid Valve Anti-Wear Lightweight Design Easily Carry 12V Brand new and high quality. Material: All Metal suitable for Car TRAIN TRUCK. Power: 12v Air Outlet: 1/4"NPT-MALE Air Inlet: 1/8" NPT FEMALE Fitting for 1/4" ID Hose Max PSI: 180 Size: 7cm x 3.1cm x 3.1cm.