The XT's monoprene blend offers the best balance of power to work ratio, providing efficient finning in high flow or stiff currents. The blade shape is designed for a wide variety of kicks, including frog kicks, modified flutter and power kicks. They are stiff, yet with plenty of snap and are lighter in weight than traditional rubber fins, meaning legs and feet won't cramp even after miles of swimming. The 8 1/2-inch pliable marine grade stainless steel spring-heel strap allows for quick donning/doffing. A comfort heel pad and convenient, removable pull tab adds to the ease of use. a lightweight marine grade stainless steel buckle secures the heel strap to the blade. The stainless steel buckle is a Dive Rite exclusive, and is guaranteed not to crack or break.