Light and swift with impact protection. Features Helion™ superfoam so running on hard surfaces never felt easier. Created without dye for a more sustainable process to eliminate waste. Cushioning: absorbs impact and distributes weight for consistent, buoyant comfort under each step Energy return: transforms every heel strike into responsive, explosive forward movement Pull-on sock upper with external lacing cage Removable memory foam insole allows for custom orthotics Speedboard™ construction moves naturally with your foot to transform every heel strike into an explosive toe-off Helion™ superfoam cushioning delivers lightweight energy return even in hot and cold temperatures