Saucony Women's Xodus 4.0 W 100% Synthetic Imported Synthetic sole Built to run around over and through the toughest of terrain Features an outsole made from Vibram XS-Trek compound coupled with an aggressive outsole design that delivers optimal performance and durability Pro-Lock, a midfoot support band, has been integrated into the lacing system for an improved overall fit Especially helpful on slippery and uneven surfaces Vibram XS-Trek outsole provides feedback on grip and geometry of terrain to prevent slipping