The 623v3 is the most athletic core training style that builds upon the previous model's features of breathabiliyt, versatility and durability, but increases the all-day comfort through a larger ABZORB heel capsule, reinforced collar foam and an EVA footbed. 10 MM drop. Automation EVA footbed. AIMEVA midsole. Internal shank. Non-marking outsole. Product Improvements: Now with even more ABZORB in the heel for more cushioning.