US sizing As is typical for Hoka, the Challenger boasts ample cushioning. It tells a lot about the brand that in the Hoka lineup this is a "medium" cushion model. The Challenger is a highly versatile shoe, as it can cover anything from trails to hard surfaces. This model is also easy to recommend for fast hiking and other walking use on trails. - Wider fit - Neutral running feel - Heel to front drop: 5 mm - CMEVA mid sole absorbs shock - Outer sole with different rubber compounds for optimizing grip - Light protection at the front - The surface is made of recycled plastic (Unifi Repreve) and the laces are also made of recycled material - Tread height 4 mm