The Brooks Glycerin StealthFit GTS 21 has the softness, stability and style for all of your runs and workouts. This plush shoe is optimized for your comfort by being lightweight, responsive, durable and cushioned. The updated knit upper not only looks great on your foot but provides a blend of stretch and compression that moves with your foot and fits a bit closer. Brooks uses their GuideRail technology to support your body in its natural motion path while keeping excess motion in check, ideal for those with flexible arches or who overpronate and like a bit of extra stability. Details Upper: An updated flat knit upper gives you a sleek fit, plenty of style and offers a blend of stretch and compression that moves with your feet. Midsole: The new nitrogen-infused DNA LOFT v3 foam gives you a plush, durable and responsive ride. A broad platform makes sure you have smooth heel-to-toe transitions. Stability: Brooks’ GuideRail® holistic support system supports your body in its natural motion path while keeping excess movement in check, similar to bumpers on a bowling alley. Outsole: New RoadTrack rubber on the outsole is lightweight, durable and includes recycled silica.