E40 to E27 Adapters of Dubious Quality 1

I got a couple of these very cheaply so I can run E27 discharge lamps in my "test cell" which is basically a 400w metal halide low bay luminaire with the gear stripped out and a socket added so I can use external gearboxes.
It often lives on top of a cabinet where it acts as an uplighter as it has safety glass.

These adapters are made from very light feeling plastic which might not like the heat of a 150w MBI or a 125w MBF/U lamp and the metal of the actual E27 socket feels a little thin.
Will do fine for what I'm going to be doing however.
I also have one similar with a G12 socket on the end.