This is my second pair of slippers from KNP. My first pair lasted nearly 3 years before I wore through the sole. I love them! I use these as house shoes for my hardwood floors in the warmer months. My feet get very hot and subsequently sweat when attempting to wear fabric or fuzzy slippers. These allow for aeration and keep my feet cool. Keep in mind you must give them some time to mold to your feet. There isn't a dedicated left or right foot starting out, but it will form to your foot. I wear a women's size 8 and a medium fits well.