Therm-a-Rest Parsec 20F/-6C review

The Parsec 20F/-6C is the strongest all-round backpacking bag in this list. Therm-a-Rest fills it with 17 oz of 900 fill hydrophobic duck down that is RDS-certified and PFAS-free, and the Regular weighs 1 lb 13 oz (820 g). Its published EN ratings are 29°F comfort and 18°F limit, close to the NEMO Disco 15 at about 1 lb less. Zoned insulation puts more down on top and around the core, and the Toe-asis pocket in the footbox is a baffled spot to warm cold feet. A YKK anti-snag zipper, a cinchable hood, draft tubes along the zip and neck, and an internal stash pocket for a phone or water filter round it out. The shell and liner are 100% recycled 20D nylon. It packs to 7 by 10.5 inches and comes with compression and storage sacks. The catches are the price, $469.95, and a mummy girth of 62 inches at the shoulder, which restless side sleepers may find snug.

Who it is for

backpackers who want a light 20°F mummy bag

Price

$469.95 for the Regular at the Therm-a-Rest store (Cascade Designs) when checked.

Regular price $469.95
Quoted from the vendor pricing page on November 12, 2026.

Key features

• 900 fill hydrophobic duck down, RDS-certified and PFAS-free
• 1 lb 13 oz (820 g) Regular with 17 oz of fill
• EN comfort 29°F and EN limit 18°F
• Toe-asis insulated foot warmer pocket
• Packs to 7 by 10.5 inches

Strengths and weaknesses

• Strength: Lightest 20°F class mummy here after the Swallow UL 20
• Strength: Packs to 7 by 10.5 inches, small for a 20°F bag
• Strength: Quilt and blanket loops let you layer more insulation in winter
• Weakness: $469.95 is more than twice the Kelty Cosmic Down 20
• Weakness: A mummy cut with a 62 inch shoulder girth is narrower than the NEMO Disco
• Weakness: Duck down rather than goose down

Key facts

• Price: $469.95 (Regular)
• EN comfort / limit: 29°F / 18°F
• Weight: 1 lb 13 oz (820 g)
• Insulation: 900 fill hydrophobic duck down
• Fits up to: 72 in (Regular)

Where it ranks

Therm-a-Rest Parsec 20F/-6C is No. 2 in our Best Sleeping Bags verdict.