【The pressure inlet is 1/4F】The water pump pressure is adjustable through this pressure switch, and you can adjust the adaptable pressure according to your needs. It is important to know that the pressure inlet dimension is not the same for all pumps. The pressure inlet nut of this pressure switch is 1/4F. 【Easy to adjust】This pressure switch has a fitting, a nut and a ring. Remove the nut and ring that will not be used. Screw the fitting into the pressure switch then screw the pressure switch onto the pump. This may not be possible if something in the pump is blocking the rotation. Get an adapter and finally it works fine. The pressure switch whose pressure inlet nut rotates freely around its axis until fully tightened. 【Automatic control】This pump pressure switch will automatically activate the pump when the pressure is below the set threshold of the pressure switch. switch, and will automatically stop the pump when the pressure is higher than the set threshold. 【High Quality