The North Face ThermoBall(TM) Traction Mule Leather The North Face ThermoBall(TM) Traction Mules deliver easy comfort and dependable warmth for everything from camp mornings to post-ride downtime. This premium leather version upgrades the iconic slip-on with a soft Oso fleece lining, lightweight insulation, and a collapsible heel for quick on-and-off convenience. Warm, durable, and packable, they&&';;re built to handle everyday errands just as well as cozy evenings at basecamp. Details Upper: Premium leather sourced from Leather Working Group-certified tanneries Insulation: ThermoBall(TM) 100% recycled polyester insulation for warmth even when wet Lining: Oso fleece collar lining for added comfort Fit: Collapsible heel with elastic side panels for easy on/off Outsole: Durable outsole made with up to 20% recycled rubber Sizes: 3.5-13, 14 Weight: Approx. 9.49 oz (269 g) per shoe