FEATURES Intermediate blade helps promote speed and increased tempo in the legs Increased resistance improves technique and builds leg power Thick foot pockets and no-slip heel grip keep the fins comfortably secured to your feet Constructed of 100% natural rubber Sizing: based on shoe size XXS: (Kid's 1-3) XS: (Men’s 3-5, Women’s 4.-6.5) S: (Men’s 5-7, Women’s 6.5-8.5) M: (Men’s 7-9, Women’s 8.5-10.5) L: (Men’s 9-11, Women’s 10.5-12.5) XL: (Men’s 11-13, Women’s 12.5-14.5) XXL: (Men's 13-15, Women's 14.5+)