The material chosen for the blade is not a traditional co-polymer but a new generation technical polypropylene that is a lot more reactive, flexible and trim. The blade is very long and has been designed specifically to get the best effort-propulsion ratio. The blade runs right along the side of the foot and has a useful surface area of 20% more than traditional blades on the same length fins.The blade thickness is not constant, it gets progressively thinner towards the end to guarantee more extensive and regular bending when in stride. The side frames are made from two separate materials that alternate and overlap in the different zones for a controlled flexibility structure in the various zones of the blade The computer-designed foot is made completely from soft elastomers for exceptionally comfortable and firm housing of the foot, to guarantee excellent transmission of the leg-fin effort. At the same time, the wide-soled foot makes it easy to remove the foot from the fin at the end of the dive and provides excellent non-slip action, very useful when putting fins on in the dry and when departing from boats or from the shore.The quick-release tilting buckles make it easy to find the perfect position for the strap on the heel. A system to lock the buckles into place prevents them from accidentally unbuckling, even when the strap is unhooked.The result of all this technology are fins that offer an excellent propulsive thrust with a truly moderate effort, perfect both for beginners and for the more advanced diver. Like all Cressi fins, Reaction offers not only fine performance in normal situations, but also makes it possible to deal with emergency situations, without giving way at all when faced with the most extreme demands for thrust.