1、The contact point of water pressure switch is silver‑plated with high‑grade pure copper conductive sheet, with good response effect. 2、How to adjust the water pressure: cut off the power firstly. Tear down the plastic cover, press "+" to Increase pressure (anticlockwise), press "‑" to reduce pressure (clockwise). 3、With high‑quality insulating material, the water pressure controller is durable and high temperature resistant, its cuicuit not easily get damaged. 4、You can choose right water pressure switch according different power requiremet and the male thread diameter. 5、The water pressure control switch could automatically maintain a constant pressure in the pipeline as well as a constant water flow. Item Type: Water pressure switch Rated Voltage: 220V Rated Current: 16A Male Thread Diameter: Approx.12.5mm / 0.5in（G1/4） Size: Approx.50 x 50mm / 2 x 2 in Pressure Range(Optional): 1.0-1.8KG (fit for 125W) 1.5-2.2KG (fit for 250W / 300W / 371W) 1.8-2.6KG (fit for 50W) 2.2-3.0KG (fit for 750W) 1 x Water Pressure Switch 1 Bag of Accessories For example (1.5‑2.2KG) technical explanation: when the water pressure is 1.5KG, the water pump will start automatically, and the 2.2KG pressure type water pump will stop working.