Walk worry free wherever you go wearing Under Armour® Surge 4 Sneakers (Big Kid). They feature polyester upper, polyester lining, and rubber insole. A round toe, lace closure, and wedge platform ensures right support at the strategic areas. The shoes have rubber midsole that allows energy bounce while walking. Rubber outsole. Imported. View Zappos.com Glossary of Terms Under Armour Kids Surge 4 Sneakers (Big Kid)