Monstrum Grimlock Mossberg 500/590/835/930/Shockwave Red Dot Mount RMR Footprint Black. All with the same functionality and reliability as standard optic mounts. The Mossberg red dot mount is a dedicated mount built specifically for Mossberg shotgun platforms. Specifications for Monstrum Grimlock Mossberg 500/590/835/930/Shockwave Red Dot Mount: Manufacturer: Monstrum Color: Black Gun Make: Mossberg Features of Monstrum Grimlock Mossberg 500/590/835/930/Shockwave Red Dot Mount Dedicated red dot mount built specifically for Mossberg shotgun platforms. Compatible with Mossberg 500/590/835/930/Shockwave shotgun models. Check full compatibility chart before purchasing. Please view compatibility chart to verify the compatibility of your red dot before purchasing. Grimlock Series optic mounts offer a sleeker and more distinctive design than previous generation mounts contoured to the curvature of your receiver. Installs directly into the factory mounting holes on the Mossberg receiver using the included set screws. No additional hardware required. Compatible with the following models: Mossberg 500 Mossberg 535 Mossberg 590 Mossberg 590 Shockwave Mossberg 590a1 Mossberg 835 Mossberg 930 Not compatible with: Pre-1997 Mossberg shotguns Requires 6x48TPI screws not included Mossbergs without pre-drilled and tapped receivers Requires drilling and tapping receiver Mossberg Maverick 88 Requires drilling and tapping receiver Mossbergs with Crimson Trace LS250 installed Requires M4-.70 x 12 screws not included Mossberg 930 Requires modifications Mossberg 500 Flex Requires modifications For direct mounting of your red dot onto your Mossberg receiver. Please view compatibility chart to verify the compatibility of your red dot before purchasing. Installs directly into the factory mounting holes on the Mossberg receiver using the included set screws. No additional hardware required. Rail is 4.5 inches or 11 picatinny rail slots in length Package Contents: Monstrum Grimlock Mossberg 500/590/835/930/Shockwave Red Dot Mount Monstrum ZD700R: Grimlock Mossberg 500/590/835/930/Shockwave Red Dot Mount RMR Footprint Black