Carlson's Choke Tubes Beretta/Benelli 20 Gauge Replacement Flush Mount Choke Tube Improved Modified. Choke Tubes made by Carlson's Choke Tubes's take lead or steel shot. With the Beretta/Benelli Replacement Flush Mount for 20 Gauge by Carlson's shot that exceeds the size of a BB should not be used in any choke tighter than modified. BB and smaller size steel shot may be used through the full choke constriction on this Carlson's Shotgun Choke Tube. Carlson's Choke Tubes has been a trusted name amongst shooters for many years because of their relentless efforts to supply the public with their premium Carlson's Beretta/Benelli Flush Mount. Specifications for Carlson's Beretta/Benelli 20 Gauge Replacement Flush Mounts: Manufacturer: Carlson's Choke Tubes Condition: New Features of Carlson's Beretta/Benelli Flush Mount Replacement for 20 Gauge: Reduces muzzle jump Less recoil Package Contents: Carlson's Beretta/Benelli 20 Gauge Replacement Flush Mounts Carlson's Choke Tubes Beretta/Benelli 20 Gauge Replacement Flush Mount Choke Tube Improved Modified 10615