Updated and upgraded with a lightweight design for greater ease of use, this boresighter package offers time- and ammo-saving convenience for sighting in your rifle. No worries about trying to get that first shot on the paper when trying a new rifle/scope combination. Also a handy way of double-checking your rifle’s zero. This system uses a 15-piece stud set to ensure precise bullet placement. With 15 studs to choose from (.177 to .45 caliber, including .204), you’re assured a snug fit in the rifle barrel, eliminating the play that leads to inaccurate boresighting. Imported.