UTG Pro AR15 6-position Receiver Extension Tube Commercial-spec Matte Black. This extension tube is machined to commercial-spec diameter for use with AR-15 style rifles. If you are looking for a top-quality receiver extension tube for your AR-15 weapon look no further than the Leapers UTG Pro Commercial Spec 6-Position Receiver Extension Tube. Crafted using 6061 T6 aircraft-grade aluminum this extension tube is guaranteed to deliver years of durability and dependable performance all without weighing you down. It also comes in an attractive black matte hard-anodized finish. Specifications for UTG Pro AR15 6-position Commercial-spec Receiver Extension Tube: Manufacturer: UTG Pro Color: Matte Black Fabric/Material: Aircraft Aluminum Gun Make: AR Platform Condition: New Country of Origin: USA Package Contents: UTG Pro AR15 6-position Commercial-spec Receiver Extension Tube UTG Pro TLU006: UTG PRO Commercial Spec 6-position Receiver Extension Tube Black