Mossberg 500 12 and 20 Gauge OverMolded Shotgun Stock - 12"e L.O.P., Black- A flat washer MUST be used with the factory stock bolt. A washer is included with the stock. The Hogue stock is designed to reuse the factory stock bolt with the addition of the flat washer. - The stock bolt (not included) is a 5-1/2"e long 5/16"e - 18 TPI with a flat washer, available at any quality hardware store, gun parts retailer, or from Mossberg directly. You must use this bolt when changing from a pistol grip or Tamer to a butt stock. Tamers/Pistol grips use a short bolt that is included with the Tamer (no washer needed). Also fits: - Model 590A1- Maverick model 88- Other Mossberg pump shotguns that are copies or variations of the 500. - 510 MiniDoes not fit: - 930 series or any other auto shotgun. - Break open guns- Flex system shotgunsPlease note: Some .410 models will not fit. Please call Hogue Customer Service to determine if the stock will fit your rifle. You may be required to provide measurements.