MIZUNO ENERZY (FOAM): Offering versatility in its application, while still maintaining softness and resilience. It will help enhance performance capabilities. Foam Wave: A Wave of comfort made of 2 layers of foam. Top layer is U4icX and bottom layer Mizuno Enerzy Foam Wave: A Wave of comfort made of 2 layers of foam. Top layer is U4icX and bottom layer Mizuno Enerzy Smooth Stretch Woven: Designed to control stretching direction for running motion and performance. Smooth Stretch Woven adapts to your foot and keeps your foot position correct. Gusseted Tongue: Stretchy tongue lining that hugs the foot securely and comfortably without any stress.