The MTL Thermo Rogue 4 is the latest iteration of our elite winter hiker - our lightest, most athletic, most durable winter boot ever. Equipped with Vibram Arctic Grip underfoot with traction lugs and a lightweight, insulated Gore-Tex upper your foot will never lose traction and stay warm in the harshest conditions. Solarcore insulation inspired by NASA spacesuits takes our warmth technology to the next level.