The water flow sensor is applied for water heater, and can be used as flow switch. Straight structure, nylon and glass fiber made, waterproof and explosion-proof, heat and cold resistant Portable size and light weight, easy to install With stainless steel ball inside of the impeller, wear-proof Three wire connection: Red for positive, black for negative, yellow for pulse signal Maximum water pressure: 1.75MPa Working range: 1-30L/min Size: Approx. 5.6*3.5*3.5cm (L*W*H) External diameter: 1.9cm Inner diameter: 1.1cm Cable length: 10.5cm Color: Black Note: Avoid strong impact and chemical erosion; Forbid to throw or collision; Install vertically, angle of inclination should not be exceeded 5 degree Medium temperature should not be exceeded 120C