• Nylon
• 0-degree Fahrenheit (-18-degree Celsius) ultralight down sleeping bag for 3-season backpacking, bike packing, and touring
• High-loft 850 fill power down insulation (Responsible Down Standard certified) with a non-PFC Ultra-Dry down treatment to improve reaction to moisture, retaining loft and performance
• Ultralight 10D shell with PFC-free DWR keeps the hood and footbox highly water resistant; breathable 10D nylon liner provides all-night comfort
• Contoured mummy shape provides adequate room for a natural sleeping position; YKK #5 zippers provide reliable, snag-free operation
• Full box baffles for maximize warmth; Sea to Summit Guarantee is offered for the Lifetime of this product