Carlson's Choke Tubes 04500 Shotgun Magazine Extension made of Steel with Blued Finish & Adds 8 Extra Shots for Remington 870, 1100, 11-87, Versa Max, V3 Carlson's Shotgun Magazine Extensions add firepower to your favorite shotgun. These magazine extensions are constructed of blued solid steel and come with spring, base clamp and a high visibility follower. The threaded tube replaces you magazine cap and gives you the ability to add extra rounds to you magazine. Fits- Remington 870/1100/11-87/Versa Max/V3.