The Therm-a-Rest Hyperion 32 Degree sleeping bag uses premium insulation to satisfy those who demand light weight but still value a good night’s sleep. It is ideal for warm weather backpacking. The bag is insulated with 900 fill Nikwax Hydrophobic Down. Down insulation has long been renowned for its compressible properties and efficiency in delivering an excellent warmth-to-weight ratio. The shortcoming of down has been its susceptibility to the effects of moisture, losing much of its performance qualities when wet or damp. Nikwax Hydrophobic down insulation provides water-repellency that keeps the insulation dry longer and allows it to dry faster if it should become wet. More importantly, it maintains thermal efficiency even if it becomes wet, a quality that could traditionally only be found in heavier, less-compressible synthetic fills. Additionally, the bag has “zoned” construction, concentrating insulation on top of the bag so you have warmth where you need it most and saving weight by minimizing insulation on the bottom of the bag where it just tends to get compressed beneath the weight of your body anyway. Mesh box baffles maximize loft and minimize cold spots in key areas. Integrated SynergyLink connectors keep your sleeping pad (sold separately) from moving away during the night. These strips are removable if not needed. A draft collar and zipper draft tube prevent cold air from sneaking inside the bag and the hood can be cinched down to keep your head insulated. Other features include a snag-free zipper, an included compression sack, and a storage sack. The Therm-a-Rest Hyperion 32 Degree sleeping bag comes in different sizes to accommodate different heights. Small fits 5’1” to 5’6”, Medium fits 5’ 7” to 6’, and Large fits 6’ 1’ to 6’ 6”.