JE Machine Tech AR Skeleton A-Frame Adjustable Buttstock Mil-Spec Black. Polymer Design Specifications for JE Machine Tech AR Skeleton A-Frame Mil-Spec Stock: Manufacturer: JE Machine Tech Color: Black Gun Model: M4 AR-15 Gun Type: Rifle Additional Features: Not CA Compliant Included Accessories: Standard Buffer Tube Size: Mil-Spec Features of JE Machine Tech AR Skeleton A-Frame Mil-Spec Stock: Adjustable Multi-Position (For Most Variants) Ambidextrous sling attachment loops and QD points Slim A-Frame Design streamlines the stock and minimizes snagging; Reduces weight while providing high strength. Polymer Design Package Contents: JE Machine Tech AR Skeleton A-Frame Mil-Spec Stock Ambidextrous sling attachment loops and QD points Rubberized Buttstock QD Sling swivel housing What firearm models does the manufacturer say JE Machine Tech AR Skeleton A-Frame Mil-Spec Stock is compatible with? The manufacturer says that JE Machine Tech AR Skeleton A-Frame Mil-Spec Stock is compatible with AR-15 M4JE Machine Tech PS-ST8B: AR Skeleton A-Frame Mil-Spec Adjustable Stock Black