The BT33 is installed with the Steel Bar Nut inside the free float tube and the 1913 Picatinny rail on the outside with the matching holes aligned. Fastened together, they allow the attaching of the Atlas Bipod or other accessories to free float tubes.
- Manganese phosphate finish on the steel bar nut.
- Hardware included.
- Available in black only.
Weight: 1.3 ounces