Touchless commercial faucets use infrared sensor technology that allows you to start the flow of water without touching the faucet. Instead, just placing your hand under the spout sensor, the sensor emits infrared beams and receives the reflection beams from the hand. Then it will give the solenoid valve a signal to open and the water will start flowing; When you take your hand away, the sensor will indicate the solenoid valve to close, then the water flow will stop. For more details, please check our blog here.