Whale diving fins are categorized into long and short styles, as well enclosed-heel and open-heel designs. Materials options are silicone, TPR, etc. As diving fins playing an important role equiping divers during underwater adventure, we quarantee that each single fin produced by us are very difficult to break as we have done thousands of break tests. Sizes are varous from XXXS up to L, in line with shoe sizing standard of America, Europe, Asia, etc.