Sighting in your rifle has never been easier. Plus, this precision-calibrated boresighter lets you check scope alignment anytime, especially important after rough trips to remote hunting locations. Select and adjust the proper barrel adapter to accommodate any caliber from .22 to .50, slide into the barrel and center the scope crosshairs or iron sights on the red dot. Crafted from anodized, CNC-machined aircraft aluminum. Batteries and instructions included.