ASICS Women's Gel-Nimbus 18 Running Shoe 100% Synthetic Imported Rubber sole Shaft measures approximately 2.5" from arch 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. FluidFit: ASICS FluidFit upper technology combines multi-directional stretch mesh with stretch reinforcements that adapt to the athlete's foot, creating a truly customized glove-like fit. Heel Clutching System: Exoskeletal heel counter provides improved support and creates improved heel fitting environment. Seamless construction