ThorlakMen's Lightweight Hooded Insulated Jacket POWERFULLY LIGHT. WEIGHTFULLY WARM. A brand new lightweight insulated jacket, built for mountain missions where every gramme counts. Thorlak is a remarkably warm, windproof and water resistant jacket, with a lightweight and packable focus. For reliable warmth even when wet, we body mapped synthetic Thermolite insulation and wrapped it in a mechanical stretch, windproof, rip stop outer, complete with a DWR