RFX Pro Series HCS Rear Sprocket Yamaha YZ125 250 YZF250 450 99 24 Various Sizes Teeth:48 CRF 450RWE 19 23 5103225 3094 CRF 450RWE 19 23 Redesigned instep and Achilles accordion flex zones construction for superior comfort Bike Year Pitch Part Number YZ 125 99 01 520 FXRS 31 48 YZ 125 05 20 520 FXRS 31 48 YZ 125 02 04 520 FXRS 31 49 YZ 250 02 05 520 FXRS 31 49 YZ 250 99 01 520 FXRS 31 50 YZ 250 05 20 520 FXRS 31 50 YZF 250 01 04 520 FXRS 31 48 YZF 250 05 11 520 FXRS 31 49 YZF 250 12 20 520 FXRS 31 50 YZF 400 99 520 FXRS 31 48 YZF 426 00 02 520 FXRS 31 48 YZF 450 03 04 520 FXRS 31 48 YZF 450 10 13 520 FXRS 31 48 YZF 450 06 09 520 FXRS 31 49 YZF 450 14 520 FXRS 31 49 YZF 450 05 520 FXRS 31 51 YZF450 15 20 520 FXRS 31 48 WRF 250 07 14 520 FXRS 31 50 WRF 250 01 06 520 FXRS 31 52 WRF 400 99 01 520 FXRS 31 50 WRF 426 00 02 520 FXRS 31 50 WRF 450 03 20 520 FXRS 31 50 RFX Pro Series HCS Steel Rear Sprocket