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.
Is this down mummy sleeping bag…?
Suitable for cooler temperatures? Yes. You would want the Spark 5°F or possibly the 18°F – either bag will work in late Fall, the 5°F will take you down to winter temperatures when paired with an adequately insulating sleeping mat like the Comfort Light Insulated.
Really suitable as a sleeping bag liner? Yes. You could use the Spark 50°F, or even the Spark 40°F or 28°F to boost the performance of a bag for cold-weather use. Adding one of these to a 20°F / -5°C bag might make more sense than buying a “0°F / -20°C” bag for only occasional winter use.
Able to be zipped to another sleeping bag? No. Even though the 18°F or 5°F have full-length side zippers, they are not designed to be coupled to a sleeping bag with a right zipper (for instance the Flame 18°F or 5°F).
Read up on the factors which define and affect down quality, and what they mean for you as an end user HERE
- Ultralight Backpacking, Bike Touring, Liner Bag
- Summer or Sleeping Bag Liner: 50°F (comfort range 50°F to 70°F)
- Warm weather: 40°F (comfort range 40° to 60°F)
- 2 Season: 28°F (comfort range 28°F to 60°F)
- 2.5 Season: 18°F (comfort range 18°F to 55°F)
- 3.5 Season: 5°F (comfort range 5°F to 50°F)
- ULTRA-DRY Down 850+ Loft 90% Down Cluster Premium Goose Down certified Responsible Down Standard (RDS)
- 10D shell and 7D liner materials help to achieve the incredible lightweight and compact packed size
- Includes lightweight Ultra-Sil™ compression bag and storage cell
- Zipper-length trimmed for gram-saving performance
- 50°F, 40°F, and 28°F have 1/3-length zippers
- 18°F and 5°F have full-length side zippers
- Baffle construction
- 50°F and 40°F have sewn-through construction.
- 28°F has baffles in the torso and sewn through in the leg area.
- 18°F and 5°F are fully baffled.