I was so glad it came with 3 different sizes. I was able to try all of them to see which one was more comfortable, turns out the medium fits better than the small for me as I first thought it would. The only reason I didn’t give it a higher star is the straps. They are elastic and lost some of it elasticity within a few weeks. There is a small clamp that comes with it to make the straps tighter. I do put in my own clip barrettes to hold the straps in place, the seem to ride up the back of my head when sleeping.