Fast & light trainer built for an ultralight, flexible and fast ride. Upgraded blend of PWRRUN, with more energy return and tougher against daily wear New geometry featuring a lower sidewall and straighter medial midfoot, designed for a smoother transition, and added comfort as you pick up the pace Our new SRS sockliner offers step-in comfort you can’t deny Breathable and lightweight upper mesh with a 3D molded heel cup for a comfortable and secure heel fit