The Midwest Industries 1913 Picatinny Rail Buffer Tube Adapter is for use with firearms that have a picatinny attachment. This product is not for use with firearms with buffer assemblies. Installs Mil-spec diameter stock tube to receivers with 1913 picatinny rails. FeaturesSuper easy installationConstructed from 6061 aluminum hard coat anodized6 position Mil-spec diameter tubeEasily accessible water proof storage in tubeSuper clean compact design