The Outdoor Research Helium UL Bivy is the updated 2026 version of OR’s popular ultralight bivy sack. A minimalist, waterproof 3-season shelter for when you travel light and fast, or as an emergency shelter alongside your tarp. Note, this is the new UL version, with a few clear improvements over the previous model.
What’s new compared to the old model
The biggest changes are in the fabric, the ventilation and the details, not the weight (that stayed roughly the same, around 511 grams):
- New shell fabric: 2.5-layer Pertex Shield NetPlus made from 100% recycled 30D nylon (bluesign approved), where the old model still used Pertex Shield Diamond Fuse. Waterproof and breathable.
- Dual passive ventilation flaps: more airflow and less condensation, new on this model.
- High-volume toe box: more room around your feet.
- More anchoring: 4 aluminium stakes and 6 stake loops, versus 2 loops on the old model.
- DAC aluminium hoop over your face, keeping the fabric off your head and giving you breathing room.
- Floor in 40D nylon ripstop with a PU coating (the old model used TPU).
In short, the UL isn’t so much lighter, but it is more sustainable thanks to the recycled fabric and nicer to use thanks to the better ventilation and roomier fit.
What the Helium UL Bivy is for
A bivy is the most minimalist way to sleep outside, small, light and pitched in seconds. The Helium UL has a clamshell opening so you climb in and out easily, No-See-Um mesh against the bugs, fully taped seams and reflective logos and trims. Ideal for fast, light trips, alpine bivies or as a backup shelter. It’s a 3-season bivy.
Specifications Outdoor Research Helium UL Bivy
- Weight: 511 grams (18 oz)
- Colour: Pewter (OR name: Light Pewter)
- Shell: 2.5-layer Pertex Shield NetPlus, 100% recycled 30D nylon ripstop (bluesign)
- Floor: 100% nylon 40D ripstop with PU coating, waterproof
- Bug netting: No-See-Um mesh
- Seams: fully taped
- Hoop: single DAC aluminium pole over the head
- Opening: clamshell
- Ventilation: 2 passive ventilation flaps
- Stakes: 4 aluminium stakes, 6 stake loops, 1 guy line loop
- Season: 3-season
- Reflective logos and trims
- Made in Vietnam
Outdoor Research does not publish dimensions or packed size for the UL version.
