Genuine Mazda thermostat for the NC MX-5
Please ensure your thermostat looks like the one shown in image
There are two types of these fitted to the NC, a long and a short type. The difference visually is very obvious, the short one is 65mm from the base to the top of the pipe, and the long type is 100mm from the base to the top of the pipe. This item is the 100mm one. Alternatively, if you are unable to see the thermostat (it is quite well buried in the engine bay!)