The harnesses in our racecars are only certified for two years. After that you have to send them in to be re certified or replace them. I always buy new and give the old ones to new racers who can't afford a new harness, but can afford the re-cert fee. Most of the time our cars reside in enclosed trailers or my shop, so UV exposure is minimal, so most times they can be re-approved for use.

Interesting reading here:

https://www.prpseats.com/replace-har...ery-two-years/