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Honda OEM Part 90508-K21-921 SCREW-WASHER (4X12)

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Honda OEM Part 90508-K21-921 SCREW-WASHER (4X12)

  • Product Code: 90508-K21-921

$0.25

  • Genuine Honda OEM part
  • New in original packaging
  • Fits the models listed in the fitment chart
  • Easy, no-hassle returns

This product is vehicle specific.

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Ships in 4 to 9 days

Genuine Honda OEM Screw-Washer (4X12) (part number 90508-K21-921) from the Rear Brake Master Cylinder diagram. It fits Honda CB500FAAC, CB500XAAC, CBR500RAAC, GROM125AAC, GROM125AC, CBF300NAAC and 27 more built from 2015 to 2026.

Fits these models

  • CB300FAC: 2015–2018
  • CBR300R5A: 2017–2022
  • CBR300R5AC: 2017–2022
  • CBR300RA5AC: 2017–2021
  • CB500FAAC: 2019, 2021–2025
  • CB500XAAC: 2019–2025
  • CB500XAC: 2019–2020
  • CBR500RAAC: 2019–2025
  • GROM125AAC: 2019–2020, 2022, 2024–2026
  • GROM125AC: 2019–2020, 2022–2026
  • CBF300NAAC: 2020–2025
  • GROM1252AC: 2022, 2024–2026
  • CB500FA2AC: 2024–2025
  • CB500XA2AC: 2024–2025
  • CBR500RA3AC: 2024–2025
  • and 18 more models

See the Fitment tab for the full list with model codes.

Need Help Finding the Right Part?

Not sure it fits? Ask before you order — our team will check the part for your machine.

For a faster answer, include:

  • Year, make and model of your machine
  • VIN or frame / serial number
  • OEM part number or a photo of the old part
Email Us (630) 886-1221

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Honda

2025

2019

Part Details

Brand Honda
Sku 90508-K21-921
Name SCREW-WASHER (4X12)

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