The Atlas BT20-B PLUS BT19 combination from B & T Industries is a precision-engineered mounting solution designed to adapt Accuracy International (AI/AICS) stocks for use with any rail-mounted bipod. The core of this setup is the BT19 Accuracy International Spigot (AAIS), which plugs directly into the rifle's factory retention mechanism and features a stable design that eliminates unwanted rotation. The BT20-B Bottom Rail then attaches to the spigot's 6 o'clock position, providing a 1.6-inch Picatinny interface machined from 6061-T6 aluminum with a Mil-Spec Type III finish. This "PLUS" configuration is ideal for marksmen who want to utilize the quick-detach levers of "LW17" style Atlas bipods or standard two-screw mounts on their AI platforms without permanent modifications. B& T Industries Atlas BT20-B Bottom Rail & BT19 Atlas Accuracy International Spigot BT20-B PLUS