The bolt-on fender for the 2021-2023 SID (35MM) C1 is part number 00.4318.094.000 (RockShox MTB Fender Black Short 2 Bolt 35mm- SID 35mm (C1+/2021+) V3).
If you need spare fender bolts, use part number 11.4018.135.000 (FENDER BOLT KIT - M3-.5X11MM BUTTON HEAD (QTY 5) - ZEB A1+, LYRIK D1+, PIKE C1+, DOMAIN B1+, SID C1+, BOXXER D1+).
RockShox service kits and spare parts are best obtained through your local shop or dealer. See our dealer locator, below, to find a dealer near you. If no one is currently listed near you, then please search for local shops via your preferred web browser.
https://www.sram.com/en/dealer-locator
Manuals and additional information about RockShox and SRAM components can be found at our service site, linked below.
https://www.sram.com/en/service
Further questions?
Reach out to Rider Support by Asking A Question at the link below.
https://www.sram.com/en/rockshox/campaigns/rockshox-rider-support