The Advanced Technology Halo Gen 2 Side Saddle Shotgun Ammunition Carrier is CNC machined from 6061 T6 aluminum and is military type III anodized. It features an integrated top rail, a sleek skeletonized side saddle design, and a nine shell configuration. Includes 8/32 screws with thread patch for Mossberg 500/590 models. NoteDirectly fits the Mossberg 500/590 12 gauge with tapped receiver. With modification, it may fit the Maverick 88, Remington 870, and Winchester SXP. Modification will require gunsmithing to drill and tap the receiver holes.