4 In. Pushfit Coupling. For connecting two pipes with internal diameters: 3.90 In. - 4.06 In. for 4 In. Sewer Pipe and DWV Connections. Internal Pushfit connection - no tools required. Can be installed in 30 seconds or less. Install in sheared off pipe where standard couplings cannot be used. No need to expose external surface of pipe. Can be removed and re-used. Watertight connection on any pipe material. Connects pipes of differing or irregular outside diameters. Pipe stop indicates that the product is properly installed, when it is flush to the pipe end. Internal lip ensures smooth transition. Rigid ABS Body provides excellent shear resistance. Ideal for the connection of plastic (SDR 35, Sch 40). Cast Iron and Copper. Does not work for SDR-26. 4.3 PSI test pressure.