Design: Upper: 100% recycled P.E.T. ripstop upper with non-PFC durable water-repellent finish to help keep feet dry Collapsible heel with elastic side panels for easy on/off In-Shoe Comfort: Lightweight ThermoBall(TM) Eco insulation retains warmth Oso fleece collar lining for comfort Durability & Traction: Sole Unit: 20% recycled rubber outsole for supreme traction Additional Details: Sizes: Medium 7-14 (whole sizes) Approx Weight ( 1/2 pair): 8.1 oz (231 g)