Shop › PHASE5 AR15 PISTOL BUFFER TUBE ASSY PHASE5 AR15 PISTOL BUFFER TUBE ASSY $59.95 Phase 5 Weapon Systems AR15 Pistol Buffer Tube Complete Assembly, Black Finish PBT-CA Quantity: Add To Cart Added! Phase 5 Weapon Systems AR15 Pistol Buffer Tube Complete Assembly, Black Finish PBT-CA