The Altra Experience Form is an exciting stability trainer for daily runs and workouts thanks to a firmer compression-molded foam and aggressive rocker shape midsole that delivers an energetic rolling sensation. Medial GuideRail technology in the midsole along with a roomy toe box make the Experience Form stable and comfy for an effortless ride every time you lace up. Details: Upper: The Experience Form features a Standard FootShape™ Fit, which falls in the middle of Altra’s three different options. The engineered mesh upper gives you a breathable fit along with a sleek and contemporary style. Midsole: With a 4 mm drop, the Form’s lightweight compression molded midsole gives you a responsive feel in combination with a rocker shape to gently roll you forward. Medial GuideRail technology gives the shoe an inherently stable ride that smooths out your stride.