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Winter camping in your dome away from home gets even better when you're wearing our toasty slip-on mules insulated with new ThermoBall™ synthetic technology. ThermoBall™ is as warm as down while delivering the wet-weather insulating performance of synthetic insulation for versatile coverage. The water-resistant ripstop exterior provides additional protection when exposed to light moisture.
Developed in partnership with Primaoft, Inc., ThermoBall is a revolution in insulation technology. Unlike traditional continuous-filament synthetic insulation, the small, round PrimaLoft synthetic-fiber clusters closely mimic down clusters, trapping heat within small air pockets to retain warmth. Independent clo testing by Kansas State University has shown that ThermoBall has warmth equivalent to 600 fill goose down. As a result, ThermoBall can offer the lightweight warmth and compressibility of down with the wet-weather insulating performance of synthetic insulation.