The Vapor V uses Scarpa's FR last, a moderately asymmetric, slightly downturned shape with a low-volume heel and a fit best for Greek foot shapes (longer second toe). The microfiber upper barely stretches, so don't count on it expanding much. Sizing varies wildly among users: some wear street shoe size, while many size down 0.5 to 1.5 EU sizes for performance. If you have a narrow heel, the LV version is worth considering for a snugger fit.