Our warmest synthetic sleeping bag for critically cold conditions, this sub-zero expedition bag provides protection in temperatures down to -40 degrees F. Constructed with a durable Pertex shell and dual-use Climashield Apex and Prism shingles with an Apex core layer, this Summit Series bag provides the highest level of protection on expedition in extreme, variable conditions where minimal weight and maximum warmth are critical.

• 20D Pertex shell
• Vaulted footbox
• Winter heat trap with center draw
• Expedition fit
• Compression stuffsack doubles as a summit pack