Complete set of (16) 7/16" heat treated (8470 Chrome Molly) press in wheel studs and lug nuts. The wheel studs are 3.5" in length and have knurled ends to make putting the lug nuts on easy and eliminate the potential for cross threading. These studs are designed for racing application and have a tensile strength of 190,000 psi.
These wheel studs are ideal for running wheel spacers. Why run wheel spacers? Because Mazda built the Miata with a wider rear track than front track so that it would understeer which is safer for the general public. Running wheel spacers will allow you to square up the car and have a better starting point than stock. The GCR now allows for different sized spacers from the front to the rear as long as they are the same size on each axle.
The lug nuts have a 60 degree taper and are zinc plated so there is no chrome to flake off after time.
Due to the complexity of the Miata stock wheel stud sizes and how they are different from front to rear based on the model year, there is not a simple solution for press in wheel studs. These studs may require that you slightly oversize drill the stock Miata hub up to 9/16" to allow the larger studs to be pressed into place.