Short circuit, overload and thermal protection. Rotary voltage selector switch. Cigarette lighter plug for car use. Supplied with 6 adapter plugs. Note: 12Vdc 2000mA (only for 24V input). Adapter plugs: 1.3 x 3.5mm/2.1 x 5mm/2.5 x 5.5mm/1.5 x 5.5mm/2.5&3.5mm jacks