Automatic Electric Car Repair Tool Kit is worth having for emergency roadside tire change and repair. Cross groove saddle prevent slipping from vehicle. Rotating threaded rod can be spin out, makes cross groove saddle closer to lifting point. In case of the power has been disconnected, self-locking power structure and safety unloading knob prevent jack from falling and will not come down immediately. When re-connecting the power, jack will go on working in accordance with the instruction, or using the safety valve manually to fall. LED lamp on jack can be used as flashlight.