O - Ring Allen Inspection Cover A.337 - AllenBrothers

O - ring Allen A.337 inspection cover Opening diameter 130mm Rubber Sealing O Ring for A.337/A.337W Rubber Sealing O Ring For A.337 hatch cover. The O ring is installed around the outside of the gasket (body) which is fixed to the hull, the lid is then screwed tight and forms a seal around the outside.