The Atlas Accuracy International Spigot (AAIS) Part number BT19 - Is designed for use with the BT10-NC Atlas Bipod that mounts directly to the AAIS which plugs into the Accuracy International AI/AICS stocks utilizing the factory retention/release mechanism. The AAIS is constructed from 6061T6 Aluminum with a type II hard coat anodize mated with an alloy steel Spigot that is finished with a Manganese Phosphate. The AAIS weighs approximately 4.7 ounces is proudly made in the USA and has a cost of $69.95. **Important** When installing the BT-19 Please be sure to Loosen the Tension Nut up as much as possible before inserting the Spigot into the stock. Push Spigot into the receptacle using the Tension Knob until there is a good solid Click of the spigot locking into place, then tighten the Tension Knob. PLEASE NOTE - our part # BT20, is a three piece 1913 rail set that mounts to the BT19 AAIS to allow any rail mounting bipod including the BT10 and BT10-LW17 Atlas bipods to be used with the AAIS. B& T Industries Atlas Accuracy International Spigot BT19