Mesa Tactical Sureshell Shell Carrier and 20" Rail for the Remington 870. These Shell Carriers & Rails hold 6 12 gauge shotgun shells and can accommodate a wide variety of optics. With the 20" rail length, iron sights traditionally used on an AR-15 can be used. The user can also mount optics with varying degrees of eye relief anywhere on the Picatinny rail. With such a generous amount of rail space, sling mounts and lights can be mounted as well. The Sureshell Carrier and Rails are constructed of aluminum with a matte black finish. The Remington 870 model is compatible with factory magazine extensions and is required on most models. Mfg: Mesa Tactical Products