power jack can be use in the DC 12V of automobile.You can easliy adjust the trunk height fastly with the power jack,which will be the necessary tool of automobile. Power jack select the tranditional gear &screw mechanism,which used the alloy steel with tenacity and anti-fray.The screw mechanism of Power jack operate under the height limit saftey.The moto of Power jack operate with the low voltage & heat& overload protection.All above prove the product has the long life and stable quality.