Originally Posted by Talfuchre
That reg tester, if I am correct, is simply an older model CCM Pump Guide Rod back (they used to be aluminum and stainless - not all stainless) that has a hole drilled in the side - to allow air in - and a second hole in the front that has been taped to take a quick disconnect.
Super simple to do if you had a lathe.
Which I do...
Sir, you are indeed amazing and correct.