This is the replacement Drive gear set screw for OS engines: / #OSMG1250: FT-300 Twin RC 4 cycle / #OSMG1300: FR5-300 5 cycle RC 4 cycle / This will also work with the FT-240 (We do not carry this engine) / / PACKAGE INCLUDES: / 1-Washer (metal) / 1-Hex screw / / sek/4-1-94