Function: (1)power inverter, small in size, can transform auto dc to ac household power supply (2)applied to digital camera, laptop. Mp3, electronic shaver, cellphone charger, etc. (3)it has protection for over-current, over-load, low voltage and high voltage Protection Features: Overload and over temperature shutdown Low battery voltage shutdown (10.5 VDC and automatic reset High battery voltage shutdown (15.5 VAC and automatic reset) Instruction: (1)no refitment to car. (2)put one of its connector into car lighter plug and then plug the electrical apparatus into the power inverter plug (3)how to change the fuse: Turn the front of plugger in anti clock direction to change new fuse. Specification: (1)input voltage: Dc12v (2)output voltage: Ac220v (3)output frequency: 50hz (4)output power: 1000w (5)twinkling maximum power: 1200w (6)woring efficency: More than 90%