Seeking long-distance relationship. 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. Features. Best for: Race Run/Speed Run. Cushioning: PWRRUN PB. • Smooth Speedroll technology for effortless speed, smooth turnover and propulsive forward motion. PWRRUN PB foam is a true unicorn, offering the best combination of cushioning and energy return of any foam on the market. Colour: black