Combination shell holder/optics rail mount for Remington 870 Express Tactical or other drilled and tapped Remington 870 models Only mounts to drilled and tapped Remington 870 or 1100 shotguns using the factory mounting holes on the receiver. If your shotgun does not have mounting holes, installation will require gunsmithing. For installation on Remington shotgun models without the factory mounting holes, we recommend installation by a professional gunsmith. Accomodates up to six 12 gauge shotgun shells Rail mount allows for the mounting of Picatinny or Weaver standard scopes, red dots, or other optics. *Note: If the forend extends past the receiver when racked back, the shell holder will not work.