The Spark™ Ultralight Mummy Sleeping Bag Series spans everything from an ultralight down-filled liner to a mid-winter fast-and-light sleeping bag. Each model uses premium materials and no-frills design to provide cutting-edge performance for the designed end-use.
Ultralight does not mean ultra-tight: The Spark mummy sleeping bags are snug but still have adequate girth for the performance-oriented backcountry user. Ultralight Backpacking, Bike Touring, Liner Bag
Summer or Sleeping Bag Liner: 50°F (comfort range 50°F to 70°F)