Constructed of type III anodized 6061 T6 aluminum, the SB Tactical® BTFA Buffer Tube Folding Adapter features a low-profile, reversible design, engineered for use with all buffer tube receptacles (except AR platform firearms). Better yet, this easy-to-install adapter locks securely in either the open and closed position, ensuring reliable lockup and enhanced stability in either position. NOT compatible with AR-style firearms. Made in USA.