A personal favorite of the Gear Shack crew when making late summer and fall trips into the high country.  You will be very hard-pressed to find another bag that provides the warmth-to-weight ratio that this one does.  The sleeping pad straps keep you on your pad all night.
 
Best Use:  Cool to cold weather trips in the backcountry when light weight is a must.
 
MSRP:  $419.95
 
From Thermarest:
Built to provide a featherlight pack weight and high-performance warmth, the Hyperion 20F/-6C is among the lightest in its class without sacrificing an ounce of performance. The bag uses thermally-efficient box baffled construction in key areas to ensure warmth and comfort in an ultralight package. Designed with high-quality materials and Therm-a-Rest performance features, the Hyperion keeps your pack light, giving you the freedom to move quickly in the backcountry. Storage sack and compression stuff sack included.
 
	
Ultralight: One of the lightest pieces in its class, the Hyperion sets a new standard for high-performance outdoor equipment.
	
900-fill Nikwax Hydrophobic Down™ : Stays drier and maintains loft 60 times longer than untreated down.
	
Unrivaled Packability: Lightweight materials and precise design allow for a smaller packed size than ever before.
	
Box Baffled Construction: Uses mesh walls to maximize loft and minimize cold spots in key areas.
	
Comfort Fit: Ergonomic shape and longer zipper provide a more human-friendly fit than other ultralight bags.
	
SynergyLink™ Connectors: Integrate the bag with a mattress for optimal efficiency and comfort; removable for versatility.
	
Zoned Insulation: Maximizes warmth and saves weight by intentionally placing fill where you need it most, 70% on the top and sides with 30% on the back.