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.

Ultralight does not mean ultra-tight: The Spark mummy sleeping bags are snug but still have adequate wiggle room for the performance-oriented, backcountry user.

Features

• 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:
• 50F, 40F, and 28F have 1/3-length zippers
• 18F and 5F have full-length side zippers
• Baffle construction:
• 50F and 40F have sewn-through construction
• 28F has baffles in the torso and sewn through in the leg area
• 18F and 5F are fully baffled