The Minwa Upswing MW293 is a DC TO DC in car voltage converter. It is used to step up the input from a 12 Volt battery to any of a range of outputs up to 24V. The DC current is regulated and the five selectable output voltages are 12-15-18-21 and 24V DC. Fitted with a cigarette lighter plug and reversable polarity connector and six interchangable plugs. Input is 12V to 13.8V DC. Output max current: 2500mA. This sort of adapter can be used for a range of things including powering battery chargers, phones, laptops, portable DVD players etc.