Full-flow, 3″ I.D. throat, no restriction. Allows for 1-1/2″ offset in any direction for closet bowl setting. Corrosion-resistant stainless steel swivel ring is engineered for maximum strength. Solvent welds over 3″ or inside 4″ Schedule 40 DWV. Fits flush to floor through any 4″ opening. UPC listed. The inside diameter of pipe can vary significantly. These flanges are designed to fit inside most, but may not fit all types of pipe.