Hammerli AP 20 Green O-Ring 2798352
This o-ring is used when changing the AP20 cylinder direction from vertical to horizontal or vise versa.
Best to replace with a new one when you change cylinder directions for best seal or to have an extra one handy if you damage it.
If this is all you need can ship in USPS Letter envelope for $1, please request this in comment field when checking out.






