Multi-tite 4" Norwesco Gasket Multi-Tite gaskets are used where pipes connect to the inlets and outlets of polyethylene, fiberglass and FRP water tanks and cisterns.
Sometimes referred to as a jones-tite grommet or gasket. Made of long-lasting neoprene. Creates a water tight seal where PVC pipes enter a cistern, water tank or rain barrel.

The 4" Multi-Tite gasket (most commonly used for tank inlets and overflow siphons) requires a 5" hole.