The North Face™ developed a partnership with Primaloft® to offer a new synthetic alternative to down. Thermoball™ is a revolution in insulation technology. Unlike traditional, continuous-filament synthetic insulations, the small round Primaloft synthetic fiber clusters closely to mimic down clusters; trapping heat within small air pockets to retain warmth.

ThermoBall™ Technology offers the low weight, loft, warmth, and compressibility of down with the wet-weather insulating performance of a synthetic.