Nike KD Vulc 2 Basketball Shoes BIG YOUTH Boys Grade School UPPER: Leather and synthetic OUTSOLE: Vulcanized rubber The KD Vulc is back and better than ever on this lightweight second edition. Featuring Flywire cables that wrap the foot for a supportive fit, this sneaker ensures a great feel all day long. Bold KD details adorn the upper, letting your little man rep the court superstar everywhere he goes. A vulcanized rubber sole rounds out this impressive sneaker update.