The B5 Systems Bravo Stack Mil-Spec Diameter, is streamlined for users who want optimal performance without unnecessary bells and whistles. The Bravo SOPMOD stock is the lightest, most effective design of its kind. The minimalist engineering and angled butt stock ensure quick and consistent placement. When you throw a gun to your shoulder, you want to reach that proper position the first time, every time. This is the minimalist's pick for peak performance.Specifications and Features: Compatible With: AR-10, LR-308 Country of Origin: United States of America Fixed or Collapsible: Collapsible Material: Polymer Mil-Spec or Commercial: Mil-Spec