This Twist Waste Commercial Twist Drain Valve with Overflow of 3½" inch, The size is 3.5 inch- 4-3/8 in flange - Inlet/Outlet (In.) 1-1/2'- overflow with cap Stainless steel drain plunger, strainer, flange, and handle Die-cast brass body - Nickel-plated - with lock nut This valve is rugged, rock-solid, drains well, snaps open & closed. These sell like hotcakes. Many sold. None returned. There are using for a commercial kitchen basin waste drain system