The North Face Thermoball (Red/Black) Post-expedition comfort should never be an afterthought. That’s why we created one of our most iconic styles—the THERMOBALL™ Traction Mules. As the original off-grid slip-ons, these warm, durable shoes were born at base camp but adapted for everyday life. Lightweight and packable for easy transportation. Insulated and fleece-lined for unrivaled comfort and warmth. These are the all-in-one solution for running errands, après relaxation or kicking-back at camp. These are an icon. 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 Oso fleece collar lining for added comfort Collapsible heel with elastic side panels for easy on/off Sole Unit: Outsole made with up to 20% recycled rubber