Nike Sunray 9 Sandal (TD) #343975-507 Synthetic UPPER: Stretchable Lycra spandex backed synthetic slip-on that is even easier for kids. Sculpted Phylon foot bed keeps the foot stable. MIDSOLE: Lightweight, Phylon midsole with Nike Natural Motion engineered flexibility. OUTSOLE: Non-marking, solid rubber outsole pods for lightweight traction. Our lightest Sunray to date features Nike Natural Motion Engineering for healthy, growth and development of our children's feet.