Stephen, this shotgun has a "Fixed Cylinder Choke" barrel.

Fixed Cylinder Choke. --- (Specifications and Features): - Mossberg Maverick 88 Security Pump Action Shotgun 31023 - 12 Gauge - 18.5" Smooth Bore Barrel - Cylinder Constriction Rate - 3" Chamber (accepts 2-3/4" and 3" shells) - 6 Rounds (5 in the magazine tube with 1 in the chamber) - Bead Sight - Cross bolt safety - Dual extractors - Twin action slide bars - Interchangeable barrels compatible with Mossberg 500 - Length of Pull 14.25" - Overall Length 39.50" - Overall Weight 7lbs - Blued Metal Finish - Black Synthetic Stock/Forend.