Brooks Beast 20 Mens Size 12.5 Gray Blue Athletic Running 。Features The Brooks Beast \'20 delivers maximum support and generous cushioning at its lightest weight yet. The Beast \'20 is the lightest Beast yet thanks to Brooks\' GuideRails technology. GuideRails act like bowling alley bumpers to keep your feet and knees properly aligned through your entire stride and mitigating excess side-to-side movement. Beneath the shoe, designers used a BioMoGo DNA midsole for responsive cushioning, while an engineered mesh upper provides breathable support. When you want a pair of Brooks running shoes for max support, the Beast \'20 is the solution.