Mares Avanti Quattro Plus Fins the evolution of the Mares Quattro fins continues in these ever-popular diving fins and now with the added advantage of new lighter materials and the popular new Mares Bungee spring fin straps making them super easy to put on and take off. The Quattro fins are the fin of choice for many diving instructors and divemasters as they give, outstanding, tried and tested performance. Anatomical foot pocket - Mares have possibly the best designed most ergonomic and comfortable fin foot pockets on the market today. Designed to help transfer energy from the foot pocket to the fin blade. The superb design principles of the original Quattro's remain the same for the new Mares Quattro Plus, optimising the thrust angle caused by the 4 channel avanti system, and incorporating thermoplastic and rubber materials. A slight difference made to the composition of these materials has produced a marginally lighter and softer fin blade than the originals resulting in reduced effort required by the calf muscles.