FOUR-RIB DESIGN FOR MAXIMUM POWER TRANSFER - Equipped with a unique four-rib structure, the Mares Avanti Quattro + Fins create an arched shape during each stroke, converting muscle energy into efficient thrust and enhancing propulsion for improved underwater performance CHANNEL THRUST TECHNOLOGY - Unique Channel Thrust inserts on these versatile open-heel fins enhance water flow, pushing more water with each kick. This design delivers powerful thrust and improved energy efficiency, making every stroke stronger without added effort THERMOPLASTIC RUBBER FOOT POCKET & TECRALENE BLADE - Constructed with a soft thermoplastic rubber foot pocket and a durable Tecralene blade, the Avanti Quattro + diving fins deliver comfort and longevity, ensuring reliable use for countless dives BUNGEE STRAP FOR EASY ON & OFF - The integrated bungee strap system on these swim flippers allows divers to slip in and out quickly, ensuring a secure fit and making adjustments simple both before and after swimming or diving ANTI-PARACHUTE PERFORATED FOOT POCKET - The perforated foot pocket on these Mares fins minimizes drag by eliminating the "parachute effect," enabling smooth, unhindered movement and maintaining consistent speed through the water