Our super warm Cirius down jacket provides backcountry hunters with a packable insulation layer for added warmth during long periods of stationary activities. Cirius is treated withKryptek Defender,a highly-water resistant treatment that offers an extra level of moisture protection for down garments exposed to wet environments. Kryptek Defender helps prevent down from clumping and losing its loft, maintaining the water repellency for the life of the garment and maximizing its ability to keep you warm and comfortable. Specifically designed to provide lightweight exceptional warmth even in damp conditions, Ciriusstays drier longer and maintains loft better than other down jackets, making it the perfect insulated jacket for a variety of unpredictable weather conditions.