This Boresighter Kit will ensure that your rifle is accurately zeroed when you're testing out a new rifle and scope combination. This system uses a 15-piece arbor set that ranges from .177 to .50 caliber and ensures precise bullet placement from the get-go. This bore sighter fits snugly in the rifle barrel to eliminate any "play" that can result in an inaccurate bore sighting adjustment and poor shooting accuracy. To use the boresighter reticle adjust the windage and elevation turrets until cross hairs line up with the center boresighter's grid. Includes hard carrying case.