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Thermarest Ohm 20F/-6C

Size: Regular

The Thermarest Ohm 20F/-6C UL is a lightweight, versatile down sleeping bag with a roomy, semi-rectangular shape for individual use or can opened up and used as a double quilt. Ideal for fast and light solo adventures in colder temperatures or for couples and group camping. 

The Ohm 20F/-6C is difficult to beat when you need ultralight weight and packability but can't sacrifice warmth and comfort. The Ohm sleeping bag, which weighs only 635g (standard length), balances out wild camping activities with a roomy fit and the flexibility to become a two-person quilt. It provides excellent warmth-to-weight performance with moisture-resistant insulation that dries quickly and compresses small, filled with high-loft 900-fill Nikwax Hydrophobic DownTMTM. Heat-mapped Zoned Insulation gives priority to important warmth areas while thermally efficient box baffled construction maintains consistent warmth distribution. High-loft down and an ultralight shell fabric keeps the overall weight and packed size to an absolute minimum.

Unusual for its class, the footbox has a full-length zipper that wraps completely around it and can be opened flat like a quilt for extra comfort and mobility on warm nights. For comfortable double bags for adventure teams, you can stack and zip together two Ohms that are completely unzipped. The Ohm keeps your pack light and adaptable without compromising on performance because it was designed with Therm-a-Rest's commitment to quality and performance.

More Help? For further assistance on choosing your down sleeping bag, we have an article explaining fill power, the pros and cons of down over synthetic insulation and more info on caring for your bag available to view here:

Down Sleeping Bags.


  • 00-Fill Nikwax Hydrophobic Down™™: PFC-free and absorbs 90% less water and dries 3x faster than untreated down.
  • Responsible Down Standard Certified: Certification that ensures the waterfowl in the down supply chain are treated humanely.
  • Unrivalled Packability: Ultralight shell material, insulation and precision design keep packed size to an absolute minimum.
  • Roomy Fit: Semi-rectangular shape cuts weight while allowing for unencumbered sleep.
  • Multiple Use Modes: Full-length zipper extends around the footbox; allows for use as a quilt, custom ventilation or mating with another Ohm sleeping bag.
  • Pairable: Stack two fully unzipped Ohms and pair them for a cozy two-person sleeping bag.
  • Refined Warmth: Box baffled construction uses mesh walls to maximize loft and minimize cold spots, while a drawcord at the collar seals in heat.
  • Compression and storage sack included.


Regular Long
Colour Balsam
Weight (Standard) 1 lbs 6 oz 1 lbs 9 oz
Weight (Metric) 0.64 kg 0.72 kg
Width (Standard) 32 in 33.5 in
Width (Metric) 81 cm 85 cm
Length (Standard) 73 in 79 in
Length (Metric) 185 cm 200 cm
Height (Standard) 4.5 in 4.5 in
Fits (Standard) 72 in 78 in
Fits (Metric) 183 cm 198 cm
Girth, Shoulder (Standard) 62 in 66 in
Girth, Shoulder (Metric) 157 cm 168 cm
Girth, Hip (Standard) 56 in 59 in
Girth, Hip (Metric) 142 cm 150 cm
Girth, Foot box (Standard) 35 in 38 in
Girth, Foot box (Metric) 89 cm 97 cm
Packed dimension (Standard) 6.5 x 8 in 6.5 x 8 in
Packed dimension (Metric) 17 x 20 cm 17 x 20 cm
EN Comfort (C) 0 C 0 C
EN Comfort (F) 32 F 32 F
EN Limit (C) -6 C -6 C
EN Limit (F) 20 F 20 F
EN Extreme (F) -9 F -9 F
EN Extreme (C) -23 C -23 C
Fill material 900 Fill Goose Nikwax Hydrophobic Down RDS 900 Fill Goose Nikwax Hydrophobic Down RDS
Fill weight (Standard) 12.5 oz 13.6 oz
Fill weight (Metric) 0.36 kg 0.39 kg
Shell fabric 10D Nylon RipStop w/ DWR 10D Nylon RipStop w/ DWR
Lining fabric 10D Nylon RipStop 10D Nylon RipStop
Zipper side Left Left

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