Designed to complement rather than replace the Vaporfly, the Alphafly Next% 2 provides runners with more energy return, impact protection, and cushion at a slightly heavier weight. What You’ll Love Widened heel for added stability Increased forefoot stack brings more energy Lightweight and supportive ride Thanks to dual, visible Zoom Air units in the forefoot, a full-length carbon fiber plate, and a higher volume ZoomX midsole, the Alphafly Next% 2 return even more energy while providing added cushioning. The Alphafly Next % 2 is refined to take all runners through the marathon distance with improved stability and smoother transition. The shoe’s heel has been widened to improve stability and smooth out transitions. The additional foam in the forefoot provides even more energy return than before. The upper features Atomknit 2.0, a material that provides an excellent lockdown in the forefoot, allows excellent toe box breathability, and provides comfort under the laces.