The Atlas BT20-B AAIS Bottom Rail is the same rail found in the BT20 kit, but consists of the bottom 1913 rail ONLY that can be attached to the AAIS BT19 (#123133 sold separately) on the bottom at the 6 o'clock position. This allows mounting of the BT10 or BT10-LW17 to the AAIS BT19. This rail is made from 6061T6 Aluminum with a type III hard coat anodize.
- Attaches to the BT19 AAIS
- Machined to Picatinny rail standards
- 1.60" Length