Mossberg Halo Side Saddle Features: - Military Type III Anodized - Integrated Top Rail - Military Type III Anodizing - 9 Shell customizable configuration Military grade reinforced synthetic material Shell holders mount in any location on the side saddle Mount as many or as few shell holders as desired Sleek Skeletonized Side Saddle Design Specifications: - Direct Fits: Mossberg 500/590 12GA with Tapped Reciever - Fits With Modifications: Maverick 88, Remington 870, Winchester SXP - Modified fit will require gunsmithing to drill and tap receiver holes. Includes 8/32 screws with thread patch Mossberg 500/590 Models - CNC Machined 6061 T6 Aluminum.