A3 Industries Utas UT9 Picatinny 1913 Rear Stock Adapter 6061 T6 Aluminum 2-Bolt Black Anodizing. Unfortunately it comes with a huge ugly buffer tube adapter on the rear that forces the user to only use AR stocks and braces. Our bolt-on Picatinny (1913) rail converts the rear of the receiver to accept any brace or stock with a Picatinny mounting interface. Specifications for A3 Industries Utas UT9 Rear Picatinny 1913 Stock Adapter: Manufacturer: A3 Industries Color: Black Anodized Gun Type: Pistol Fabric/Material: T6 Aluminum Attachment Type: Picatinny Mount Type: Picatinny Features of A3 Industries Utas UT9 Rear Picatinny 1913 Stock Adapter Machined from 6061 aluminum and hardcoated low-gloss black. Easy 10-minute installation. Package Contents: A3 Industries Utas UT9 Rear Picatinny 1913 Stock Adapter A3 Industries RSA024: Utas UT9 Picatinny 1913 Rear Stock Adapter 6061 T6 Aluminum 2-Bolt Black Anodizing