Bring on the white stuff. Where MK comes from, the extreme weather separates the pros from the amateurs, and provides the ultimate test for testing worthy outerwear. The Double Down Series is what they wear. Made with a unique washable, waxed poly twill fabric, it's uber-durable and weather-resistant, and insulated with 650 fill power grey goose down. Relaxed fit. Mid-weight warmth, 5 pockets, adjustable cuffs.