Open PVC, 3″ hub/inside 4″ flush to floor, closet flange with corrosion-resistant stainless steel swivel ring which is engineered for maximum strength. 1-piece plastic. The inside diameter of pipe can vary significantly. These flanges are designed to fit inside most, but may not fit all types of pipe. No. 887-PM: Type: Open Closet Flange, Size: 4″X3″, Schedule: Schedule 40 DWV, Material: PVC