An electronic (touch) bathroom sink faucet differs from its mechanical counterparts in that it has no levers or valves. Simply placing your hand near it starts the water to flow. The automatic water on/off switch is activated by a built-in infrared sensor that detects hand movement within its range. The shut-off valve is controlled by the sensor, and the temperature and water pressure... https://avahome.pk/product-category/flush-tanks/