Mizuno Enerzy Foam has higher reactivity and more elastic quality than the previous running EVA technology - U4ic and U4icX. A lighter, more cushioned iteration of U4ic that provides a softer underfoot feel for a smooth transition. Found in Wave Enigma, Wave Inspire, Wave Rider and Wave Prophecy. U4icX Strobel Durable Plate. Durable carbon rubber for extended wear. Made of foam for comfort and support.