The SB Tactical Pistol Brace Open Tube is the perfect addition to your pistol and pistol brace. The Tube attaches using standard AR-15 receiver extension threads and is ideal for use with non-AR pistols adapted to use AR buffer tubes. The 6.125" length is offers the most compact package possible. Please note that the open-end design will not accept an AR-15 buffer/spring assembly. Ideal for AK-Style pistols, CZ Scorpions and other non-AR platforms.