Water flow sensor consists of a copper body, a water rotor, and a hall-effect sensor. When water flows through the rotor, rotor rolls. Its speed changes with different rate of flow. The hall-effect sensor outputs the corresponding pulse signal. This one is suitable to detect flow in water dispenser or coffee machine. Life is longer than plastic body. Features • Compact, Easy to Install • High Sealing Performance • High Quality Hall Effect Sensor • RoHS Compliant TypeDimensions(DN)Working VoltageFlow Rate RangeLengthMale & FemaleLength of ThreadMaterial YF-B1 DN15 5V~15V(DC) 1~25L/min 44mm Double Male 10mm Copper YF-B2 DN15 5V~15V(DC) 1~25L/min 50mm Male in Female out 10mm Copper YF-B3 DN15 5V~15V(DC) 1~25L/min 66mm Double Male 18mm Copper YF-B4 DN15 5V~15V(DC) 1~25L/min 66mm Male in Female out 10mm Copper YF-B5 DN20 5V~15V(DC) 1~30L/min 50mm Double Male 10mm Copper YF-B6 DN20 5V~15V(DC) 1~30L/min 60mm Double Male 11mm Copper YF-B7 DN15 5V~15V(DC) 1~25L/min 66mm Double Male 10mm Copper G1&2 DN15 5V~24V(DC) 1~30L/min Double Male Plastic G3&4 DN20 5V~24V(DC) 1~60L/min Double Male Plastic G1&2 DN15 5V~24V(DC) 1~30L/min 60mm Double Male 13mm Plastic G1&8 - 5V~24V(DC) 0.3~6L/min - - - Plastic M11*1.25 - 5V~24V(DC) 0.3~6L/min - - - Plastic