Combined with the infrared sensor module, it detects an object approaching or moving, and the water dispenser will work automatically. When there are no pets, it will remain still. Yilean external sensor (without adapter or cat water dispenser) fits all cat, dog and pet drinking fountains with USB interface. For indoor use only. Do not touch the water. [ Energy Saving; Super Quiet ] Yilean infrared motion sensor provides practical, safety, energy saving and convenient functions. This device uses the infrared radiation emitted by the pet as a signal to work when the pet is within the detection range. Reduce the noise of the cat and dog water dispenser, extend the life of the fountain pump, and stimulate pets' interest in drinking water. [High stability] Yilean cat water fountain sensor switch has a wide detection range, detection angle: 180°, detection distance: about 3M. High and stable sensitivity, effectively save energy and improve efficiency. Wide time range: 30s (fixed shutdown