Features: Good sealing effect, easy to install. Make of copper, durable, anti corrosion, high temperature resistant. Mainly used for water flow switch control of electric appliances such as water heaters, humidifiers, drinking fountains. When this product connected to a load above 50W, intermediate contactor-relay must be added, otherwise it cannot be used. Working method: When there water flowing in the water flow switch and the water flow rate 1.0L/min, the magnetic core in the water flow switch will receive water. The flow pushes the displacement, and the magnetic core displacement drives the magnetic source to produces the magnetic control effect, so that the water flow switch output "on" Signal. The signal input to the equipment control system, and the control system realizes the control function. When the water flow less than the starting flow, the water flow switch outputs a "off" signal. The control system produces the samereverse control. Specifications: Interface Size: 4 points (G1/2) Inner Diameter/Outer Diameter: 15mm/20.5mm Thread Length: Long Teeth 18mm Short Teeth 10.4mm Material: Copper Max-Switch Current: 0.5A Max-Load-Current: 0.5A Max-Contact Resistance: 100mg Max-Load-Power: 50W Max-Load-Voltage: 220VDC (DCVoltage) Minimum Collapse Voltage: 220VDC (DCVoltage) Start-up Water Flow1.5L/MIN Working Water Flow Range: 1.5-30L/MIN Start Water Pressure0.1Mpa Minimum Withstand Water Pressure 1.75Mpa Working Environment Temperature 1~120C Applicable Ambient Temperature -20~150C Response Time: 0.2S Release Time: 0.2S Size: Approx. 2.4x6.2x2.9cm/0.94x2.44x1.14in Note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Water Flow Sensor