Hoka Bondi 4 Running Shoes - AW16-10 - Grey fabric Layered Lycra no sew upper Construction - An absence of seams reduces the number of potential weak points throughout the shoe that would otherwise be prone to tearing or breakage. Lightweight Breathable Air Mesh Upper - Allows air to fully permeate the shoe, promoting a cooler, drier and altogether more pleasant environment. Comfort Collar - Extensive padded panelling prevent the foot from rubbing against the collar, thereby reducing blisters. Super Soft and Lightweight EVA Strobel Board Lasting - A robust, lightweight construction cushions and supports the foot superbly. Early Stage Meta-Rocker Geometry - specifically engineered with a low heel-toe differential and a sculpted outsole radius in the heel and toe, encourages a guided foot gait cycle; supports a runner's form and running mechanics.