You can find the Adaptive Tactical Shell Carrier for Mossberg 500/590/88 here Fast $9.95 shipping! Orders over $200 ship for free!

The Adaptive Tactical Shell Carrier for Mossberg 500/590/88 12 Gauge shotguns is simple, sturdy and can hold 6 shells at the ready. Quickly and conveniently reload right from the side of the receiver. The streamlined, lightweight design features a shaped mounting plate which fits closely to the receiver's contours.