Comparison : Item # 30C-SW-23-G, 3 Inch (in) Nominal Size Iron Pipe Size (IPS) Standard Wall Aboveground Fiberglass End Cap with Gasket Joint
Item # 60C-HW-23-G, 6 Inch (in) Nominal Size Iron Pipe Size (IPS) Heavy Wall Aboveground Fiberglass End Cap with Gasket Joint