This is the OEM Crosman Power Adjuster (for 22xx series) that has been
modified to accept an oversized thumb screw.
You have your choice between Stainless Steel
and Solid Brass screws.
The stainless screw is much wider and about the same depth vs the OEM
The brass screw is much thicker, but about the same diameter vs the OEM
For the steel adjuster body itself, you have your choice of OEM blued
or fully polished and waxed.
These can also be turned down for the thinner tube on the pump guns (13xx, 2289).
wider, same depth stainless steel
thicker, same diameter solid brass
Any of the power adjusters can be fully
polished, as shown above.
These are shown with normal-sized thumb screws.