Go the distance on hot days running hard-packed trails in the S-Lab Sense 4 Ultra. Designed for athletes competing in the Western States 100-Mile Endurance Run, the S-Lab Sense 4 Ultra is optimized for long, scorching trail races. The fourth edition of this proven winner sports an all-new upper material of quick-drying, extra breathable open mesh to keep feet cool. An enhanced toe bumper, ProPriotection and ProFeel Film work in conjunction to keep feet protected while soaring over rugged terrain. The Contagrip outsole utilizes specialized rubber densities, and a redesigned lug pattern helps shed mud better and grip into hard-packed earth mile after mile.