The Thermarest Hyperion Sleeping bags are lightweight and packable down insulated sleeping bags for those looking to get the most warmth for weight. Constructed from ultralight 10 denier Nylon ripstop with a DWR treatment which is low bulk meaning the bag can be packed down impressively small. The Hyperion bags are insulated with 900FP responsibly sourced goose down with a Nikwax hydrophobic treatment. This noes not mean that the down is waterproof but it does significantly improve its performance in damp conditions. The Hyperion bags feature Box Wall baffle construction. This enables the down to loft fully and eliminates the stitching cold spots that you get on regular stitch through construction. The down in the Hyperion bags is zoned to maximise insulation and minimise weight. 70% of the down is on the top and side baffles, and the remaining 30% is in the baffles that would be on the bottom of the bag. Removable SynergyLink connectors allow you to attach your bag to a sleeping mat, holding it in place while you wriggle around in your sleep and holding you on the mat. the long side zip had a full length baffle to stop yout body heat escaping through the zip. Thermarest Hyperion 20F Features 10D Nylon Ripstop fabric 900 FP RDS Goose Down Nikwax fluorocarbon free Hydrophobic Down Mummy taper shape Long zipper Zoned down distribution Compression stuff sack
