Challenge the trail in the versatile and all-conditions-capable Challenger ATR 6 GTX. From trail running to smooth street strides, the Challenger ATR 6 GTX is dynamically designed for traction on both, using its distinctive outsole and zonal construction to optimize grip. | Features. GORE-TEX bootie. Unifi REPREVE recycled yarn. Gusseted mesh tongue from recycled materials. Early stage Meta-Rocker. Compression-molded foam midsole. Vegan. Toe Rand. Recycled poly laces. Zonal rubber. 4mm lugs.