NIBCO | sku: 92757 Nibco 6 In. X 4 In. Pvc Dwv Spigot X Hub Flush Bushing The NIBCO 6 in. x 4 in. PVC DWV Spigot x Hub Flush Bushing can be inserted into a PVC sitting hub to reduce the hub to a smaller pipe size. The bushing is designed for use with drain, waste and vent piping systems. PVC fittings exhibit high corrosion and... Log in for pricing