Delta 621TPA3350-SS 620TP Electronic Lavatory Faucet with Proximity Sensing Technology - Battery Operated in Stainless With Proximity Sensing Technology, the entire faucet body acts as a sensor, activating water flow when hands approach and stopping once hands are removed. The reliable, hands-free activation responds extremely fast regardless of lighting, reflections or approach direction. Products featuring Proximity Sensing Technology are ideal for tough conditions requiring superior vandal resistance as well as ease of cleaning and maintenance. - FEATURESSingle hole installation - Optional 4in cover plate available for 3-hole installation, order separately - Cast brass, gooseneck spout - Surface mount control box included>