Shop › MESA SADDLERAIL 4" MOS 6-12GA MESA SADDLERAIL 4" MOS 6-12GA $129.95 Mesa Tactical 6-Shell Side Saddle, 12 Gauge, SureShell Saddle with Rail, Fits Mossberg 500, 590, Black 93630 Quantity: Add To Cart Added! Mesa Tactical 6-Shell Side Saddle, 12 Gauge, SureShell Saddle with Rail, Fits Mossberg 500, 590, Black 93630