The Flyin' Miata reroute thermostat is held in place by a retaining ring - a small but important piece that keeps the thermostat retained properly. It's not a part that is commonly damaged, but when you need one, it can be surprisingly hard to find. This ring will fit all FM reroutes, but probably won't fit other brands.
This is a good replacement for a missing ring or a smart spare to keep on hand when servicing a reroute system. Toy car not included.
