Airsoft outer barrels have a notoriously sloppy fit with inner barrels. Your accuracy is directly tied to how stable your accuracy components are. Pair this with the o-ring mod for an absolute zero wobble ROCK SOLID barrel for maximum accuracy. Simply drive this wedge between your inner and outer barrel at you rifle's muzzle, trim the excess, and replace your flash hider. This is one of the few mods out there which you can really see huge improvement right away with very little work. This is an excellent companion product for the R-hop.