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 Eco Friendly Materials: Recycled materials Gusseted Tongue: Stretchy tongue lining that hugs the foot securely and comfortably without any stress. MIZUNO ENERZY (FOAM): Offering versatility in its application, while still maintaining softness and resilience. It will help enhance performance capabilities.