This fitting was salvaged from a brewery, they were classed as outdoor fittings, they were ment to have an outer glass clear tube that the fluorescent tube was contained in, the ends have screw fittings with rubber rings that grip the outer glass tube to seal. Made by the original Thorlux company, classic fitting, they dont rust as they are powder coated and galvanized

Me and my mate had a load of these from an industrial site don't ever know what happened to them sadly

Love it

Me too! Might be possible to find some replacement overtubes from someone like Encapsulite.