The Real Avid Bore-Max Smart-Fit Bore Guide is a spring-loaded precision cleaning tool for centerfire rifles from .223 to .375 caliber. The spring-loaded tube and 3 interchangeable tips provide consistent chamber sealing to prevent chemicals from leaking into the action. 2 included action locking keys lock the Bore Guide in place and fit a variety of long-action and short-action platforms. Tube is made from anodized aluminum for durability. Works with centerfire rifles from .223 to .375 caliber Fits a variety of long- and short-action platforms, ARs, etc. Spring-loaded tube and 3 interchangeable tips provide consistent chamber sealing Prevents chemicals from leaking into the action