Go faster on the trail with the Altra Superior 4. 0 Trail Running Shoe. The newest version of this lightweight trail shoe has gotten even lighter, and hasn't sacrificed any performance in doing so. The upper has been completely redesigned in a wrap-around style for a snug and supportive fit, and the new lighter-weight midsole features Altra's Quantic foam for cushioned comfort and support on your long trail excursions. For trail-specific features you've got ultra-grippy MaxTrac rubber on the outsole, along with a redesigned lug pattern for uncompromising traction on all the variable surfaces you'll be zipping over. There's also a protective underfoot rock plate that keeps your feet guarded from sharp rocks and roots, and removes easily if you're trying to lighten the weight on mellower terrain. A hook-and-loop attachment tab lets you easily attach a compatible ankle gaiter to keep trail debris from sneaking in your shoe. You've got all that plus Altra's foot-forward design, featuring a Zero Drop platform for a healthy stride and a Footshape toe box that lets your toes splay out naturally for a healthier foot motion and better ground control on the trail.