Kits include a weld-in or bolt-in bung and an easy grip O-ring cap with positive seal. Kits are often used as an inspection plug or a filler plug.
Small fill plugs have a 1-3/8 Inch opening, and large fill plugs have a 3 Inch opening. This large kit has a 3 Inch opening with a 3-12 thread, a steel weld-in bung and a polished aluminum cap.