Helly Hansen. Our essential adventure jacket, waterproof, windproof and breathable. The essential adventure jacket, Loke is versatile and ready for mountains, forest and beyond. We built it to withstand changeable weather with our trusted waterproof and windproof yet breathable HELLY TECH® construction. We added a front storm flap to further shield you from wind and rain, and vents to prevent overheating. Fully adjustable cuffs, hood and waist let you adjust the fit and comfort for year-round outdoor activity.