If you have a flared breacher barrel model, please see this product for the correct rail.
This rail system offers three, 3-slot picatinny rails for Mossberg 590/590A1/Shockwave 12-gauge firearms. This kit includes a rail system machined from solid 6061-T6 billet aluminum and steel swivel screw. Both items are coated with color-matched Cerakote ceramic coating to match the firearm's factory finish and for increased durability. Attaches over the magazine cap for an easy 30-second installation. (Optics shown not included)
*May require modification on models with choke systems. Not compatible with bayonet installed. Not compatible with Streamlight TL Racker or Magpul forend installed on 14" barrel Shockwave*