... " ,5" ,6" ,7" ,8" O.D.Stainless Steel Cleanout cover plate with machine screw,polished stainless steel.Countersunk hole will accept both ... 5/16" screws.Face of plate cover with protective paper.plate comes with 1/4"-20x4" plated machine screw.Plate size.: 3" , 4" ,5" ,6 ...