Residential electronically controlled faucets eliminate the need to touch or turn handles and the temperature and flow rate can be pre-set. Through the use of sensor beams, the automatic faucet determines when an object is in front of it and automatically turns on the faucet. Since there is nothing to touch and nothing to reach for, an automatic faucet eliminates all of that cleaning and disinfecting that you do to try to maintain a hygienic surface. The automatic faucet provides water only when needed. Additionally, since these faucets are preset to shut off after approximately 30 seconds, accidental flooding can't occur if a person leaves it running. And, because they are hands-free, they help reduce the spread of germs and keep the vanity area clean. Fits all standard faucets. Uses 4AAA Alkaline Batteries (purchase separately). Water pressure: 0.5 - 7.0 KGS/cm, 10-125 psi.