G&G GGG-1074 Mossberg 500/590 Late GGG-1074 Post '97X 40mm Mount Low profile design MIL-STD-1913 configuration Perfect for mounting a tactical scope to your Mossberg 500 and Mossberg 590 shotguns Easy installation to factory drilled and tapped receivers, or receivers drilled and tapped for 8-40 threads Attaches with four steel Torx head screws. Torx wrench is included