As I recall, these were in the 8mm range. I was simply told to pick out the "screamers". Rather subjective, to say the least, when you are pawing through vats of round white metallic pearls. I went for the ones that had super-mirror luster and orient reminiscent of iridescent soap bubbles. My eyes were pretty tired at the end of the day, but I can't wait to see what PP does with "Sheri's Screamers"!!!