Twist Handle Waist Drain, Sink Opening 3-1/2", Drain Outlet 2" Nps, Face Flange 4-3/8" Od, Actual Dimension Of The Top Is 4-3/8", Current Inventory Does Not Have An Overflow Outlet., We Will Be Out Of The Multi-Use Twist Drain Untill Later In, This Year 2014., You Can Substitute A Lever Handle Drain # 56-1376.., Which Includes The Overflow Outlet If Needed.,