SPROCKET SPROCKET COMPATIBLE WITH MODEL: CS451 CS452 CS500 CS510 CS550 CS610 BELL INDEX: 77.5mm BORE THICKNESS: 14 mm TOTAL HEIGHT: 28.5mm 3/8" 7 TEETH ROLLER CAGE 37507 SELF-ALLINATING RING 18720 ECHO CODE: 21358X ORIGINAL CODE: AT