Specification: Max.power control:1.5KW(around 2HP) which means this switch works with pumps (such as well pump ,submersible pump,submersible pump self-priming pump Vacuum pump,Air compressor )which is 2HP or the power of the pump less than 1.5KW. Suitable for 0-85m stroke water pump . Join screw: NPT 1/4"MALE . It comes with the pressure adjustable modes; Freely easy adjust pump Starting pressure (lower limit ) and Stop pressure (upper limit). It doesn't have the run dry facility. It can be fitted to the water pump, well pump, submersible pump, submersible pump self-priming pump Vacuum pump, and so on.