When fashion and function come together seamlessly.Who helped you fall in love with running? A cheering parent? A PB-dedicated friend? We're all seeking relationships that go the distance. The Endorphin Speed 4 is here to fill the role. Designed as a race-day shoe, it's quickly proven itself much more, equally capable during long, moderate training sessions and sprints to the finish. Thanks to the "just right" combination of winged nylon-plate, SPEEDROLL technology and PWWRUN PB foam, the Endorphin Speed 4 provides the perfect balance of support, rebound and forgiveness. Mile after mile, it's the one that will always show up for you.Smooth SPEEDROLL technology for effortless speed, smooth turnover and propulsive forward motionPWRRUN PB foam is a true unicorn, offering the best combination of cushioning and energy return of any foam on the market. Striking that 'just right' feeling - firm enough to propel, soft enough to cushionRe-engineered winged nylon plate for vertical reinforcement