TYR CrossBlade fins are designed as a multi-purpose training fin. The intermediate blade length combines the attributes of both short and long blade fins. Increases temp and speed while still offering increased resistance to build leg power. Whether you seek technique work or increased power, the CrossBlade is the fin to meet your training needs. Great all-around practice fin. Combines the attributes of both short and long blade training fins. Perfect for race-pace training. Allows you to maintain arm and kick tempo at higher speeds, imitating race-speeds in practice. Soft rubber foot pocket conforms to foot. Extended size range from youth to adult. For females, size down 1 to 2 sizes.