The TruGlo TG941XB Magnum Gobble-Dot Xtreme is a premium fiber optic sight set designed specifically for Mossberg 500 835 and 9200 shotguns with 3/8" vent ribs.TruGlo TG941XB Magnum Gobble-Dot Xtreme Sight SetRed front fiber optic sight (.060" diameter)Green rear fiber optic sight (.035" diameter)CNC machined steel frame constructionNon-magnetic fiber optic designCompatible with Mossberg 500 835 9200 shotgunsDesigned for .37" vent rib configurationPerfect for turkey hunting and sporting applications this sight set provides enhanced target acquisition with bright fiber optic visibility in various lighting conditions.