THIS MEN’S SHOE IS FOR: The Glycerin Stealthfit 21 is for runners who want a snug, close-to-foot fit and supreme softness in every step — so they can get lost in the comfortable ride and run distraction-free. This Brooks Glycerin Stealthfit 21 has been granted the APMA Seal of Acceptance. Predecessor: Brooks Glycerin Stealthfit 20. SUPREME SOFTNESS: Now with even more super-soft nitrogen-infused DNA LOFT v3 cushioning that is optimized to be lightweight, responsive, and durable with plush comfort. SECURE, ADAPTABLE FIT: Updated flat knit upper Stealthfit construction offers a blend of stretch and compression for a closer fit which provides seamless structure, breathability and adapts to the movements of your foot. SMOOTH, STABLE TRANSITIONS: The broad platform stabilizes your foot and promotes smooth heel-to-toe transitions for a supremely soft on-the-run experience. BREATHABILITY: Flat Knit upper provides a seamless fit that allows for maximum breathability to keep your feet comfortably cool. For supreme softness and do-it-all design, look no further than the Glycerin Stealthfit 21. Made with our softest cushioning, now with even more nitrogen-infused DNA LOFT v3, this shoe features a comfortably snug and adaptable that comfortably moves with your foot.