SIZE CHART: XS 31-32: shoes length about 17.5cm S 33-35: shoes length about 18.5cm M 36-38: shoes length about 20.5cm L 38-41: shoes length about 21.5-22.5cm XL 41-44: shoes length about 23.5cm XXL 45-47:shoes length about 24.5-25.5cm Please measure your foot length before ordering. We suggest you to choose one size bigger than our size chart. ATTENTION: NOT MEANT TO USE ON SHARP OR HARD SURFACES SUCH AS CEMENT, ROCKS OR PAVEMENT A PERFECT FIT: Stretchy polyester Spandex uppers allow our water socks to conform to the shape of your foot, so our swim socks won't get in the way of your activities AMPLE PROTECTION: The neoprene soles on our socks keep the bottoms of your feet safe and insulate your feet to keep you warm QUICK DRY FABRIC: Our swimming pool socks dry off quickly, meaning no soggy wet socks inside of your shoes IDEAL FOR ANY ACTIVITY: Wear them as pool socks, surf socks, scuba socks, fin socks for snorkeling & more!