3 in. x 4 in. Techno, PVC Closet Flange, With Adjustable Stainless Steel Ring and Knock Out, Test Cap. features a unique inset test cap that cannot be damaged by construction equipment, ensuring drain lines stay securely covered until installation and DWV (drain, waste, and vent) testing are complete. The Techno Knockout is specially designed to break out in one piece and will not fall down the drain line while it is being removed. Compatible with both 3- and 4-inch Schedule 40 DWV pipe, this toilet flange has a Flush-Tite design that allows for flush installation inside of 4-inch pipe.