Karhu Flow 4 Trainers deliver an efficient mix of a lightweight feel and excellent response. The durable forward ride puts emphasis on propulsion and speed.A new one-piece air mesh upper creates an incredibly cool, flexible and comfortable environment for your feet. Ideal for neutral runners.Upper: Moisture wicking collar liner and dual-pronged memory foam heel provides a dry and comfortably locked-in fit. Lightweight, breathable near seamless one-piece air mesh upper. Lace-up front offers an adjustable fit. Midsole: EVA padded lasting board under sockliner provides added cushioning. Directly-placed EVA fulcrum assists in efficient transition through gait cycle. Injection-molded, wearable EVA midsole provides lightweight performance, traction and durability.Outsole: Compression rubber outsole in key abrasion areas offers added durability.