MONTANE Prism Bootie - SS17 Pertex outer, Primaloft Insulation PERTEX Microlight Rip-stop outer fabric - 100% windproof and provides a water repellency. 160g PRIMALOFT GOLD insulation - Throughout the Bootie upper that is warm, packable and exceptionally fast drying. PRIMALOFT GOLD Insulation with Grip Control - In the inner sole panel to prevent insulation slipping and providing better stability. Soft brushed microfleece lining - Wicks sweat away from the surface of the skin, while providing insulation. Adjustable ankle - For a close, comfortable fit.