The GEL-CUMULUS 28 shoe is a lightweight running shoe that's designed to provide a smooth underfoot experience.FF BLAST MAX foam is one of our most energetic cushioning technologies. This material is designed to help create cloud-like landings and a responsive toe-off during your run.A FLUIDRIDE outsole material is strategically placed to provide smooth transitions between strides. An AHAR LO material is also positioned in the heel area for added traction and durability in high wear areas.