Welcome to the Vortex, the perfect lightweight Sleeping Bag made for hiking into basecamp. This unique Browning Bag uses a top layer filled with waterproof down, and a bottom layer filled with synthetic TechLoft Micro insulation to give you the best of both. The ultra-lightweight TechLoft Micro insulation has a tremendous weight-to warmth ratio. And its RDS-certified 600-fill-power waterproof down prevents it from clumping up. Includes a compression stuff sack.