AC Fans /DC Fans /Blowers /WireFanGuards /PlasticFanGuards /FanPowerCords /FanFilters Wire Form Fan Guards Back Part Number: TWG-120 For use with fan size Rib Material Dia. Ring Material Dia. Mounting Hole Centers (M/C) Outside Ring Dia (OD) mm in mm in mm in mm in mm in 120 4 1/2 2.31 .091 1.80 .071 104.8 4.13 115.6 4.55