AIM Sports Inc 6 Round Side Shell Carrier Kit/Mossberg 500/590/600. This Shell Carrier by AIM Sports Inc holds up to six 12 gauge shotgun shells and all mounting hardware is included. The AIM Sports Inc 12 Gauge Shotgun Shell Carrier has a quick detach design and easy to install. Improve your efficiency by keeping your shells at your fingertips with the AIM Sports Inc Mossberg 500/590 Shell Carrier. Specifications for AIM Sports Inc 12 Gauge Shotgun Shell Carrier: Length: 7" Width: 2.4" Weight: 5.03 oz Features of AIM Sports Inc Mossberg 500/590 Shell Carrier: Holds up to six 12 gauge shotgun shells Quick detach design All mounting hardware included Black polymer (carrier) Black anodized aluminum (mounting plate) Package Contents: AIM Sports Inc Six 12 Gauge Shell Carrier AIM Sports Inc MM6RK: 6 Round Side Shell Carrier Kit/Mossberg 500/590/600