TacStar's SideSaddle places shotshells right where you need them for both quick and easy reloading. The Slimline SideSaddle features a streamlined aluminum back plate with a non-glare anodized finish which has been contoured to take less space on the receiver and has fewer areas that could potentially snag. It that mounts directly to the back side of the receiver. The shell carrier is also smaller than the traditional SideSaddle, and is made of flexible, synthetic rubber for durability and weather resistance. This model fits 12 gauge Mossberg 500 and 590 models.