Choate Tool Mossberg 500 Long Forend w/Picatinny12 Gauge. To attach our rail at 3-6-9 oclock position you simply use a Phillips head screwdriver and screw in 4 screws provided. It accepts all tactical light mounts that fit on 1913 picatinny style rails. Fits the Mossberg 500 shotguns with 7 3/4 inch forends. Our forends only fit the Mossberg shotguns that have the steel tube in the center that the action bars are welded to. If your forend is held to the action bars by pins and there is no steel tube in the center of your forend when it is removed from the action then our forend will not fit your gun. Specifications for Choate Tool Mossberg 500 Long Forend w/Picatinny: Manufacturer: Choate Tool Gun Make: Mossberg Gun Model: Mossberg Model 500 Gun Rail: Picatinny Included Accessories: Standard Country of Origin: USA Gauge: 12 Gun Type: Shotgun Quantity: 1 Features of: Glass filled polymer construction Picatinny rail section included Picatinny rail can be mounted at the 3 6 or 9 o'clock position Package Contents: Choate Tool Mossberg 500 Long Forend w/Picatinny What firearm models does the manufacturer say Choate Tool Mossberg 500 Long Forend w/Picatinny is compatible with? The manufacturer suggests that Choate Tool Mossberg 500 Long Forend w/Picatinny is compatible with Mossberg Model 500Choate Tool CMT-02-02-22: Mossberg 500 Long Forend w/Picatinny12 Gauge