DaFiN is the most powerful and comfortable fin in the water today. DaFiN was developed in Hawaii by Andy Cochran, an Aussie who was one of Oz's early surfing pioneers. Cochran worked closely with two of Hawaii's most famous watermen, Mark Cunningham and Brian Keaulana, on the design of DaFiN. DaFiN delivers top performance for lifeguards and bodysurfers. It is the most popular fin with watermen around the world. DaFiN was recently featured prominently in the critically acclaimed bodysurfing film 'Come Hell or High Water'. Da Fin? is the only swim fin endorsed by the United States Lifesaving Association, the premier professional association of beach lifeguards and open water rescuers in the United States. Dafins Weight: 1.3 – 3.0 lbs per pair (example: size ML = 2.4 lbs per pair) Size Chart XX-Small (M: 1-2 / W: 2-3.5)X-Small (M: 3-4 / W: 4-5.5)Small (M: 5-6 / W: 6-7.5)Medium (M: 7-8 / W: 8-9.5)Medium-Large (M: 9-10 / W: 10-11.5)Large (M: 11-12 / W: 12-13.5)X-Large (M: 13-14 / W: 14-16)XX-Large (M: 15-16 / W: 16-17.5)