For endless energy on mountain runs, push your limits with Boost energy-return. A low-to-the-ground, sock-like upper with a Continental rubber outsole delivers grounded support and extraordinary grip. Upper: Speed lacing construction for fast and snug lacing. Midsole: Pro-Moderator - thin TPU film on the heel for extra stability. Inlay: Molded Ortholite sockliner. Midsole: Boost offers endless energy in the mountains and high adaptability on rocky surfaces. Outsole: Continental Rubber for extraordinary grip. Material: Textile, Rubber.