4 in diameter strainer plate. 2 in IPS plastic tailpiece allows adjustment to desired finished level. Key hole slots in clamping collar allows clamping of membrane without removing bolts. Weep holes in clamping collar allow secondary drainage if leaks occur around strainer. Fits over 2 in or inside 3 in Schedule 40 DWV. Heavy duty 4-1/4 in Screw-Tite stainless steel strainer.