(31H9Y5) ThermoBall Traction Botties - Ponderosa Green Medium Icon Plain PriThermoBall Traction Botties by North Face Women's. Warm and comfortable ThermoBall Eco insulation pairs with high traction rubber outsoles to make these slip on booties ideal for base camp, aprs ski, or shuffling through the snow to grab the morning paper. Upper: Recycled P. E. T. ripstop upper with non PFC durable water repellent (non PFC DWR) finish to help keep feet dry Lightweight ThermoBall Eco insulation retains warmth even when wet Easy on off