Biker boots in 100% cowhide leather with buckle details on the upper. Side buckle closure. Flexible insoles in 100% sheepskin. Rubber soles. LEATHER: The material used to make each product has its own unique features. Any possible markings or color variations are signs of the authentic nature of the leather used. STARFIT® TECHNICAL FOAM INSOLE: Flexible technical insole made with polyurethane foam. Comfort, cushioning, and durability.