Automatic touch-free sensor eliminates cross contamination. Meets barrier-free accessibility standards. Sensor detects user's hand to automatically dispense controlled amount (0.8ml) of soap; activation range is 4" from sensor lens. Reduces soap usage, waste. Bright polished chrome spout cover. Red LED light blinks when soap refill is low. Yellow LED light blinks when battery life is low (average battery life 100 soap refills or 2 years). Water-resistant battery compartment and motor housing. AC adapter is 6V. Mounts through 1" diameter hole in lavatory or countertop. Maximum countertop mounting thickness 2". Requires 4 alkaline D Cell batteries (not included). Spacer for use with lavatory rim 3/4" or greater included.