Choate Tool Moss 10 Shot Magazine Extension12 Gauge. These kits are constructed of solid steel.. PLEASE NOTE: The 9200 extensions must have special shell follower. If ordering for a mod 9200 please call us at 800-972-6390 to place the order so we can get you the right follower. Kit includes : Magazine Extension Barrel Clamp High Visibility Shell Follower and Spring. Specifications for Choate Tool Moss 10 Shot Magazine Extension: Manufacturer: Choate Tool Magazine Capacity: 10 Round Gun Make: Mossberg Country of Origin: USA Features of: Steel construction Package Contents: Choate Tool Moss 10 Shot Magazine Extension Mag extension Mag tube spring High visibility shell follower Clamp Choate Tool CMT-02-04-05: Moss 10 Shot Magazine Extension12 Gauge