When you're counting ounces and pushing your limits, take the Mountain Light 20 on your next outdoor adventure. Our most technical bag, the Mountain Light is designed for 3 season use. Ultralight fabrics and high fill power down combined with a traditional mummy shape provide incredible warmth in an extremely compressible package.. . . . . 750 Fill Power Downtek Water Resistant Down. Ultralight 20D Ripstop Nylon shell and 15D Nylon lining. Vertical Baffling with down gates to eliminate cold spots and prevent unwanted down migration. Two-way zipper with anti-snag draft collar. Zippered exterior headlamp/cell phone pocket. Internal hood drawcord makes it easy to cinch tight and trap heat. Compression sack and mesh storage bag included. RDS-certified down ensures humane treatment of ducks and geese. ISO Comfort: 30degF / -1degC. ISO Limit: 19degF / -7degC. ISO Extreme: -14degF / -25degC. Shell: 20D Ripstop Nylon. Liner: 15D Nylon. Insulation: 750FP Downtek Down. Fill Weight: 530g. Total Weight: 975g. Fits up to: 6'1". Imported.