Samson 040614301 B.R.E. (Bufferless Receiver Extension) Black Anodized with Folding Picatinny AdapterThe B. R. E. The Samson Bufferless Receiver Extension with picatinny folding stock adapter is a 6 position adjustable carbine buffer tube designed to seamlessly integrate with mil spec AR 15 carbine stocks. Folding Mechanism can be removed and reattached for right side fold. Attach to the Brownell's BRN 180, Sig Sauer MCX, Sig Sauer MPX and other buffer less set ups. Stock not included.