Samson B.R.E. MP5K End Cap Folding Bufferless Receiver Extension Ambidextrous Black. The B.R.E delivers a sleek lightweight design that enhances maneuverability and stability. Compatible with mil-spec AR-15 adjustable carbine stocks and braces. Specifications for Samson B.R.E. MP5K End Cap Folding Bufferless Receiver Extension: Manufacturer: Samson Gun Type: Rifle Gun Make: Heckler & Koch Gun Model: Heckler & Koch MP5K Color: Black Finish: MIL-A-8625 type III class 2 anodizing Caliber: 9mm Luger Hand: Ambidextrous Length: 6.36 in Weight: 10.2 oz Stock/Brace Material: 6061-T6 Aluminum Features of Samson B.R.E. MP5K End Cap Folding Bufferless Receiver Extension Compatible with mil-spec AR-15 adjustable carbine stocks and braces. 6 position adjustable. Easy yet sturdy push button folding mechanism. Ramp to drastically improve ease of installing stock. Skeletonized Package Contents: Samson B.R.E. MP5K End Cap Folding Bufferless Receiver Extension What firearm models does the manufacturer say Samson B.R.E. MP5K End Cap Folding Bufferless Receiver Extension is compatible with? The manufacturer suggests that Samson B.R.E. MP5K End Cap Folding Bufferless Receiver Extension is compatible with Heckler & Koch MP5KSamson 04-06164-01: B.R.E. MP5K End Cap Folding Bufferless Receiver Extension Ambidextrous Black