Carlson's Shotgun Magazine Extensions For Home Defense, Tactical and Law Enforcement Use, 12ga Only 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. Easy to follow instructions are included. The magazine extension tube is great for home protection, competition shooting, and law enforcement. Overall Length of Extensions: 04500 (8.25-inch), 04501 (10.5-inch), 04502 (6.25-inch), 04503 (6.375-inch), 04504(1 4.25-inch), 04505 (8.25-inch), 04506 (6.25-inch), 04507 (8.25-inch), 04508 (5-inch), 04510 (13.88), and 04511 (8.5-inch), 04518 (14.25-inch) **Magazine round count is for the total capacity using 2 3/4-inch shells and 1 in the chamber ** **Remington extensions require removal of tabs in magazine tube on newer model shotguns** All extensions are 12 gauge only.