Altra Superior 4.0

The Superior 4 takes an already lightweight, fast trail shoe and makes it even lighter. The upper has been completely redesigned in a wrap-around style for added security and support; the midsole features Altra’s proprietary Quantic™ foam, while the outsole is now made of our sticky MaxTrac™ rubber. To top it off, the rounded heel and improved lug pattern is made to fly down the trail with ease and speed. - Insole: 5 mm Contour Footbed - FootShapeTM Toe Box with Fully Cushioned Zero Drop PlatformTM - Stack Height: 21 mm - Midsole: Altra QuanticTM - Outsole: MaxTracTM Rubber with TrailClawTM - Upper: Seamless wrap-around engineered knit - Insole: 6 mm Contour Footbed with removable StoneGuard™ - FootShape™ Toe Box with Fully Cushioned Zero Drop™ Platform - Stack Height 21mm - Midsole: Quantic ™ with InnerFlex™ - Outsole: MaxTrac™ with TrailClaw™ - Upper: Wrap-Around Knit FOOTSHAPE™ TOE BOX Allows your toes to relax and spread out naturally for more comfort and stability in uphill climbs and downhill descents. ZERO DROP™ PLATFORM Places your heel and forefoot the same distance from the ground to encourage proper, low-impact form throughout your trail run. GAITERTRAP™ Hook-and-loop tab allows strapless gaiter attachment that prevents debris from building up beneath the shoe. TRAILCLAW™ Canted lugs positioned strategically beneath the metatarsals to provide traction at toe off.