New in this update is full lenghth NITRO ELITE foam for the top layer, which along with NITRO sandwiches the new carbon PWR-Plate (70% Carbon, 30% TPU) that is lighter and works better with your body's natural biomechanics. The heel rubber is now PUMAGRIP ATR for even more durability. Improved heel counter to ward off any heel slip. Lighter than its predecessor with improved fit, foam, and plate. V2 is ready to cushion and propel you with improved efficiency for all distances from shorter runs to marathons.