Zurn Exposed, Top Spud, Automatic Flush Valve, For Use With Category Urinals, 1.0 Gallons per Flush ZER6003AV WS1 CPM In Corner Compartments The door to the dispenser The door to the dispenser closes with a stainless steel piano hinge and is outfitted with a standard Bobrick keyed tumbler lock to prevent theft of the towels inside The dispenser is made from Type 304 heavy gauge stainless steel with a satin finish to reflect light while showing less fingerprints and smudges 4" NPT (top or bottom supply) these flow control devices don't require user contact to activate Their sensor automatically triggers flushing after a set time period or once a user has moved out of sensing range