ASICS Women's Gel-Cumulus 18 BR Running Shoe 100% Synthetic Imported Rubber sole Mpact Guidance System (I.G.S) (Running) : ASICS design philosophy that employs linked componentry to enhance the foot's natural gait from heel strike to toe-off FluidRide: FluidRide provides the ultimate combination of bounce back and cushioning properties with reduced weight and exceptional durability Rearfoot and Forefoot GEL Cushioning Systems: Attenuates shock during impact and toe-off phases, and allows movement on multiple planes as the foot transitions through the gait cycle Guidance Trusstic: This Trusstic System: integrates Guidance Line construction for enhanced gait efficiency while providing midfoot structural integrity Guidance Line: Vertical flex groove decouples the tooling along the line of progression for enhanced gait efficiency