Super-soft cushioning with industry-leading support for supreme comfort. The Glycerin GTS 21 delivers weightless softness with added support with the adaptable GuideRails support technology. The latest Glycerin features more nitrogen-infused DNA LOFT v3 cushioning than before to magnify the plushness and elevate softness to new levels. FEATURES: Made with recycled materials equivalent to 5 plastic water bottles. New RoadTack rubber includes recycled silica and is lightweight and durable Additional 2mm of DNA LOFT v3 midsole for a plush ride Supreme softness Now with more super-soft, nitrogen-infused DNA LOFT v3 cushioning that is optimized to be lightweight, responsive, and durable for plush comfort. Improved fit New, engineered warp knit upper is breathable and allows for a flexible, accommodating fit while staying soft against your foot. GuideRails holistic support system Our innovative technology supports your body in its natural motion path while keeping excess motion in check.