Kalso Earth Women's Interact Slip-On Shoes Leather Anatomic arch support helps deliver a natural walking motion. Eco-friendly BioFoam insole provides exceptional cushioning. Thermoplastic rubber outsole offers durable slip resistance and stability. Leather upper, spandex upper lining, Impertex (polyester) sockliner, BioFoam insole... Thermoplastic polyurethane rubber outsole.