The BT20-B Atlas Accuracy International Spigot Bottom Rail is the same rail found in the BT20, but consists of the bottom 1913 rail ONLY. It attaches to the bottom of the BT19 AAIS via blind threaded 10/32 holes and has a two hole pattern of 1.100″ (see third image).

To utilize the quick detach lever on our “LW17” style of Atlas Bipods OR the 2-screw mount style of Atlas Bipods, it is compatible with the following:

• Any ARCA clamp with a matching hole pattern. We offer Area 419’s ARCALOCK Clamp separately OR together as a complete unit: BT20-B/ARCALOCK Clamp (see fourth image)

• Any Picatinny clamp with matching hole pattern. We offer American Defense’s ADM-170-S separately OR together as a complete unit: BT43 Leveraged Rail (see fifth image)

• Arisaka’s Picatinny Rail Slider

Machined to Picatinny rail standards from 6061-T6 aluminum with Mil-Spec Type III Class 2 finish. Available in black only. NO HARDWARE INCLUDED. 10-32 x 3/8″ Flathead Socket Screws available separately.

• Length: 1.60″
• Weight: 0.57 ounces