The SL-100 uses super strength, rare earth magnets to hold the laser securely, within the bore for consistent accuracy. Various size o-rings are used to guide the precision stainless steel muzzle adapter in the bore with no metal ever touching the rifling. The anodized, aircraft quality, aluminum housing contains the laser which is precisely aligned to the center of the bore.
The SL-100 fits .22 to .50 caliber bores plus 20 and 12 gauge shotguns without having to buy extra arbors or sleeves. They are boxed in a rugged carrying case and have an Unconditional Lifetime Warranty...no matter what!