Maximum speed for your race day Take your performance to the next level with the Endorphin Pro 4. The snappy SPEEDROLL technology ensures explosive propulsion and an incredibly fluid running sensation - stride for stride. Thanks to the proven carbon plate, you benefit from maximum efficiency and a smooth transition at any speed. The new SRS (Super Responsive Sockliner) insole brings additional reactivity and comfort directly under your foot. The redesigned upper with integrated tongue and silky-soft heel insert gives you a snug, race-ready fit - made for high performance. Put them on once and all you want to do is accelerate.