Bravo Company Mfg Pistol Receiver Extension for AR15 Black BCM-Pistol-RE. This extension works with AR15 rifles with a collapsible-stock receiver extension adapter. The BCM Pistol receiver extension allows the shooter to keep a tight chamber on a pistol buffer tube without the pistol extension. It does this by making the receiver extension a receiver-to-bolt-cartridge which is a common occurrence on AR15 pistols. The receiver extension provides the shooter with a tactile feel in the shoulder a tell-tale feature for a BCM buffer tube. Pistol receiver extension removes the gaping case between the buffer tube and the pistol receiver extension clamps the buffer tube and the lower receiver. This allows the shooter to have a positive clamping surface for the recoil lug to sever the buffer tube from the receiver extension clamp. Specifications for Bravo Company Mfg Pistol Receiver Extension for AR15: Manufacturer: Bravo Company MFG Color: Black Gun Model: AR-15 Package Contents: Bravo Company Mfg Pistol Receiver Extension for AR15 What firearm models does the manufacturer say Bravo Company Mfg Pistol Receiver Extension for AR15 is compatible with? The manufacturer suggests that Bravo Company Mfg Pistol Receiver Extension for AR15 is compatible with AR-15Bravo Company Mfg BCM-Pistol-RE: Pistol Receiver Extension for AR15 Black