FX Impact M3 & M4 air rifle quick tune lock nut ring.

This is a custom small lock collar to which locks the hammer spring adjustment thumb wheel off so it cannot be adjusted without undoing the grub screw in the side – this stops accidental movement of the power wheel and also helps lock it in place/stop slight creep. With the lock fitted you are still able to turn the main power wheel, but you are unable to adjust the quick tune part using the thumb wheel without undoing the grub screw lock first.

The lock does limit your hammer spring adjustment slightly.

Its made from aluminium and anodised in black.