The Men's Brooks Glycerin GTS 21 Running Shoes are designed for the ultimate super soft underfoot feel. These running shoes feature an additional 2mm of nitrogen-infused DNA LOFT v3 cushioning, ensuring a super soft feel with every stride. The breathable yet flexible engineered warp knit upper provides an accommodating and soft fit, adapting to your foot's natural movement. Incorporating the GuideRails technology, the Men's Brooks Glycerin GTS 21 Running Shoes keep your feet and knees in proper alignment, promoting healthier running.