Yes, a replacement damper is available for the 2025+ Domain C1.
00.4318.063.010 DAMPER UPGRADE KIT - ISOLATOR RC, CROWN, 3-POSITION, OPEN, PEDAL, FIRM (INCLUDES COMPRESSION AND REBOUND DAMPERS) - DOMAIN 38MM C1+ (2025+)
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