Its not weightless, but the ultralight, three-season Vesper feels pretty darn close.

Built to provide a featherlight pack weight and high-performance warmth, the Vesper 32F/0C quilt thrives during ultralight, backcountry adventures. The quilt uses thermally-efficient box baffled construction to ensure warmth and comfort in an ultralight package. Designed with high-quality materials and Therm-a-Rest performance features like a SynergyLink Connector, a snap neck closure, perimeter side baffles and an insulated footbox provide warmth and comfort in the backcountry. When compared to sleeping bags, the Vesper quilts save weight and pack smaller by utilizing the warmth of your insulated mattress. Storage sack and compression stuff sack included.

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.
SynergyLink Connector: Integrate the quilt with a mattress for optimal efficiency and comfort; removable for versatility.
Draft Protected: Perimeter side baffles, snap neck closure and insulated footbox eliminate unwanted drafts.
Responsible Down Standard Certified: Certification that ensures that the waterfowl in the down supply chain are treated humanely.

Color: Ether
Weight: 440 g
Fits: 183cm
Girth Foot: 94 cm
Width: 147 cm
Length: 191 cm
Packed dimension: 13cm x 15cm
Comfort: 5°C
Limit: 0°C
Fill: 900 Fill Goose Nikwax Hydrophobic Down, RDS
Fill weight: 240 g
Liner fabric: 10D Nylon w/ ThermaCapture
Shell fabric: 10D Nylon w/ DWR