This unique hybrid sleeping bag features a top layer filled with waterproof down and a bottom layer filled with synthetic TechLoft Micro insulation to ensure a comfortable and warm night?s sleep. Our TechLoft Micro insulation consists of multiple denier staple-length fibers that have a siliconized finish for maximum insulation, loft, and compactness. It is an ultra-lightweight insulation that has a tremendous weight-to warmth ratio. The Vortex uses RDS certified 600-fill waterproof down which adds water resistance and prevents the down from clumping. The Vortex has No. 8 separating zippers and an insulated chest and zipper baffle. For durability, there is a polyester ripstop outer shell and a soft polyester liner. The included compression stuff sack makes packing a breeze. The Vortex is offered in multiple temperature options accommodating a variety of hunting and camping seasons. The Vortex is a perfect light-weight bag for hiking into base camp or spike camp.