FITS: Mossberg 500/590/Maverick 88. Simple and sturdy the Adaptive Receiver Mounted Shell Carrier for Mossberg keeps six 12 gauge shells at the ready. No need to fumble for shells just quickly and conveniently reload right from the side of the receiver. Whether for home defense sport shooting or law enforcement use the durable shell carrier is up to the task and ready to perform in the harshest of conditions.The Receiver Mounted Shell Carrier is also available for Remington pump action shotguns. IMPORTANT FOREND ADVISORY: If your shotgun is equipped with a field grade forend that extends onto the sides of the receiver it will hit the shell carrier and not cycle fully. To remedy; shorten the length of the forend or equip with an alternate compatible forend such as Adaptive’s EX-Performance or Wraptor.