It is a 120W Buck Converter/Power Supply Module/Car Adapter, Input voltage: DC 24V (DC 17 ~ 40V), Output voltage: DC 12V, Output current: 10A, it has waterproof, damp-proof and shock-proof, overcurrent, over-temperature, low heat and dissipate heat protection, troubleshooting automatically resume work, very suitable for buses, CMB, large trucks, motor car so on.