Taylor Forge in Kansas furnished launchers and receivers on a project a few years ago. Search for the closure that you prefer and specify it before you issue the inquiry. Assure that you define compatible and incompatible o-ring material too. When the closure o-ring material furnished by Taylor Forge was determined to be incompatible with the sour gas, Taylor would not replace the o-ring on their nickel. This is a very large o-ring the cercumference of the closure.