I have that exact torch and gas lense in liquid cooled format. Very good setup. Pyrex cup is very fragile, so buy a few spares NOW before you get halfway through a job and shatter one because you set the torch down a little too hard.
I’ve got another that the torch is about 1/2" long from the back of the torch head to the tip of the tungsten and has a little 1/4" diameter pyrex cup that I always fucking break. I have to grind and cut pieces of tungsten that are a hair over 3/8" long :lol