It is a Car Charging Module/20W Adapter, Input voltage: DC 12 / 24V, Output voltage: DC 3.7~12V (Adaptive), Output current: 4.2A, Suitable for USB DGP applying 1.2V / 2.7V on D+ and D- lines, Apple devices, Samsung devices, Car audio, radio, monitoring walkie-talkie, LED display, solar energy generation, photovoltaic panels, industrial equipments and etc.