b'Xeleros Guidance PropulsionSystem GPS . The Propulsion element cradles the rear foot and extends forward to guide the foot into a neutral position throughout the gait cycle. The Carbon Fiber Slingshot propulsion plate provides torsional stability, keeps the foot CUSTOM FIT in alignment, and helps to SYSTEM reduce impact pressure. The dual layer X-Lite midsole provides cushioning and speeds up heel to toe transition.X-LITE SHOCK ABSORPTION REARFOOT & FOREFOOT CARBON FIBER AND UNDERFOOT STABILITYROCKER TORSIONAL STABILITY LIGHTWEIGHT , HIGH ABRASIONFOOT FRAME RUBBER OUTSOLE MIDSOLEEVA-PU FORMULA = CUSHIONEDSTABILITY'