Malone Specialty Inc. offers Carbon Steel British Parallel Hollow Hex Plugs, as well as 316 Stainless Steel British Parallel Hollow Hex Plugs, in various sizes. These Hex Plugs comply with ISO 228-1 specifications. This item comes with an Elastomer, or Form-E seal, and is to used for a port application purposes only. It will NOT seal on a 60° ball seat.