Air Stripper. 1/2" UNF Natural Aluminium.

The air strippers have the option of a natural, black anodised or brass cone.
20.5mm outside diameter
Body length 71.5 mm with 14mm thread
Body length 77.5mm with 20mm thread
The cone has 8mm forward / backwards adjustment.
If your barrel has 14mm thread or less choose airstripper with 14mm thread
Or if barrel thread is over 14mm choose 20mm thread length.