Therm-a-Rest Ohm™ 20F/-6C Sleeping Bag

The Therm-a-Rest Ohm 20F/-6C is an ultralight mummy bag filled with 900-fill Nikwax Hydrophobic Down at a 360 g fill weight, EN/ISO 23537 tested to a 0°C comfort and -7°C limit rating. Box-baffle construction prevents down migration and keeps insulation even along the length of the bag, while a total weight of 635 g makes it one of the lightest three-season bags in its temperature class. A full-length two-way zipper lets it open completely flat as a quilt, or zip together with a second Ohm to form a double bag — useful for couples sharing a trip. Both shell and liner use 10D nylon ripstop to keep weight down, at the cost of lower tear resistance than heavier fabrics; the material is also DWR-treated, the down is RDS certified, and the construction is PFC-free. Maximum user height is 183 cm. It suits ultralight backpacking and thru-hiking in milder conditions where minimizing sleep-system weight is the priority.