National Geographic Snorkeler accessories are constructed from materials at the leading edge of water-wear technology. The fitted neosock is an amazingly comfortable and practical solution to improved performance and comfort from your fins. The plush neoprene inner sole and carefully placed seams make for optimal comfort and the non skid pattern on the sole make for improved footing.The heavy duty mesh scuppers allow for ease of draining. The neoprene uppers makes for non chaffing and an easy fin fit, accommodating from a size 5 through 12.