Named for the 50K ultra race, Hoka One One Speedgoat running shoes are built to handle and perform well in rugged conditions and on technical trails. The upper provides support all the way through the forefoot and the ground-rubber toecap provides increased toe protection. Ultrarunner and ultrarunning coach Karl Meltzer inspired the performance and construction of these shoes.Upper: Lightweight No Sew SpeedFrame construction provides security between the foot and the upper on any terrain. Welded synthetic overlays offer lightweight support. Welded microfiber underlays provide lightweight comfort. Padded heel collar enhances comfort.Midsole: Durable, injection molded EVA. Balanced Meta-Rocker Geometry helps increase the economy of running performance and helps promote an accurate foot roll through the gait cycle. Removable insole. Outsole: Vibram® Rubber Outsole with 4mm lugs. Trail Specific Outsole flex grooves provide stability.