Upper: Upper made with 100% recycled P.E.T. ripstop with a non-PFC durable water-repellent (non-PFC DWR) finish for added water repellency.  THERMOBALL™ 100% recycled polyester insulation helps keep feet warm even when wet.  Sole Unit: Non-marking Vibram® XS Trek rubber outsole for the optimal balance of traction and durability