This pump is compatible with All Portable Car washer (Suitable for JPT, StarQ, Gaocheng,Ballorex, CAZAR, Vantro, Btali, Aimex Pressure washers) Package Contains: Car washer head with auto-cut off switch Comes assembled with spring and piston to provide excellent pressure and smooth functioning. It's a spare part to be replace if your washer is facing pressure issue, etc