Product DescriptionThe CMMG Receiver Extension (carbine buffer tube) is designed for MK4 and M4-style AR-platform builds, providing the correct interface for compatible collapsible stocks and proper buffer system alignment. Finished in black, this receiver extension is a dependable replacement or upgrade for completing a lower receiver build or refreshing worn components.Product Highlights CMMG receiver extension (buffer tube) for MK4 and M4 carbine-style AR-platform applications Black finish to match common AR builds and lower receiver components Ideal for completing a lower receiver build or replacing a worn receiver extension Designed to support use with compatible carbine buffer and spring systems Genuine CMMG part for consistent fit and functionSpecs Brand: CMMG Manufacturer Part Number: 55CA9D7 UPC: 816422020676 Type: Receiver Extension (Buffer Tube) Compatibility: MK4; M4 carbine-style AR-platform Color: Black Weight: 0.5 lbDisclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product's manufacturer.