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.