What puts the wonder into WonderWelly ? FitFlop sets out to turn an iconic silhouette into the world s comfiest rain boot with our biomechanically engineered technology. They ve contoured the sole to evenly distribute bodyweight, filled the hollowed-out heel with our innovative honeycomb design that absorbs the impact of every step, and placed high-rebound micro springboards in the forefoot to help put a spring in your step. Here in the short version.