Under Armour Kids Surge 4 Sneakers (Big Kid) Zappos.com Under Armour Surge 4 AC Running Shoes Unisex Childrens Runners Under Armour Kids Infant Surge 4 Alternate Closure (Toddler) (Black Under Armour Preschool Boys' Surge 4 Shoes Academy. The Under Armour Boy Infant Surge 4 Alternate Closure Sneakers offer a perfect blend of comfort and support for your little one's adventures. Featuring a breathable mesh upper and a TPU heel overlay, these shoes ensure a durable and supportive fit. The hook and loop strap closure allows for easy wearing, while the cushioned EVA midsole delivers all day comfort. Crafted with a rubber outsole, these sneakers have a flat heel under 1", providing a reliable and lightweight footwear option for babies.