Made from blued solid steel, Carlson?s Shotgun Magazine Extensions include everything you need to install: spring, base clamp, and a high visibility follower. Simply replace your magazine tube cap and spring to add rounds to your shotgun?s capacity with ease. This magazine extension fits Remington 870/1100/11-87 shotgun models.Features:12 shot capacity with 2-3/4" shells;Made from blued solid steel;Includes spring, base clamp, and high-vis follower;Polymer follower, steel tube and spring;Ideal for home protection, competition, professional use