662 Fin Inserts are a 2mm fin sock combined with a Fin Pad. This is a hybrid design that keeps both comfort and functionality in mind. With the new, slim fit, they eliminate the need for combining multiple bulky fin accessories. They come in a variety in sizes to accommodate every rider. Small- men's shoe size 4-6. 5 Medium- men's shoe size 7-9 Large- men's shoe size 9. 5-11 X-Large- men's shoe size 11. 5-13