Pictured on the left of the 3 spikes in the photo.

Zinc with nickel finish. These can be placed squarely to the strap edge, or spin them 45 degrees so they cover all the angles. Tips are pointy, so beware of getting poked or scratched by them. For size reference, image shows pyramids installed on a 1 inch wide leather strap. Spikes are 0.325 (3/8) inch tall.

Consider adding all 3 heights of this type of spike available in ascending or descending order on a collar for interesting visual effects. Beware: long hair will catch on these.

If you are unsure of the quantity of studs that will fit your strap, you may either inquire first, or order more than you think you need. I can refund an overage, but not charge more for extra (unless you make a new order, which is more complicated for both of us).