Waterproof Danner Dry liner pulls moisture away from the foot for greater comfort ; Rubberized EVA midsole maintains the same cushioning properties as traditional EVA, but is more durable and won’t break down as easily. This technology enhances rebound, comfort and support. Cushioning polyurethane OrthoLite footbed is removable and provides comfort and underfoot support Vibram SPE midsole enhances rebound, comfort, and support under your foot TPU heel frame provides lightweight support and stability ; Fit Tip:Mountain 600 fits slightly large and we recommend sizing down a half size for best fit. Vibram Fuga outsole features self-adapting lugs and Mega Grip compound for superior grip on both wet and dry surfaces