ATI Remington 7 Shot Fluted Aluminum Mag Extension with Swivel Stud CapExpand your Round Capacity to 7 shots with ATI’s Aluminum Mag Extensions for Remington 870 12 Ga Shotguns.Features:- Constructed of Military Type III Anodized, 6061 T6 Aluminum- Virtually Indestructible- Minimum Barrel Length of 18.5” for 7 Shot Extension - Includes Magazine Spring- Easy Installation- Ratchet Base for Tight Fit- Fluted Design- Includes Mag Extension Swivel Stud Cap- Outside Diameter of the Extension is Engineered to Match the Diameter of the Shotgun Barrel Lug- Manufactured in the USASpecifications:- Fits: Remington 870 12 Gauge Shotguns- Color: BlackNotes:- Holds an Additional 2 – 2 3/4 Shotgun Shells - Sling Swivel Studs Accepts ATI's Sling Swivel (Part Number A.5.10.2506) or any Standard Sling Swivel