FIXED SPROCKET SPROCKET COMPATIBLE WITH ECHO MOTORWHEELS MODEL: CS450 CS451 CS451VL CS452 CS500 CS550 CS600 CS610 FEATURES: PITCH: 3/8" TEETH: 7 Ø INNER BORE: 14 mm HOLE LENGTH: 12.8 mm Ø INNER BELL: 77.50 mm BELL HEIGHT: 13.80 mm BEARING: 10X14X13 ECHO code: 54.230.0503 original code: CZ