Rain is rarely the problem; your own moisture usually is · review
Outdoor Research Helium Bivy review
The only listing here to publish two deniers and name its membrane — and one that gives no dimension, no weight, no packed size and no waterproof figure.
A slate-colored bivy in Pertex Shield Diamond Fuse 2.5L, a 100% nylon 30D ripstop upper over a 100% nylon 40D floor with TPU lamination, with a bluesign approved polyester mesh. That is the entire published specification.
What the fabric block does say
30D upper, 40D floor. The hub intro sets this out as the pattern to look for, and this is the only listing here that publishes both numbers. The heavier floor is the part that survives being pitched on gravel.
A named membrane. Pertex Shield Diamond Fuse in a 2.5-layer construction, rather than the unnamed laminates elsewhere in the hub.
What is missing
Everything else. No length, no width, no height. No weight. No packed size. No hydrostatic head behind the word waterproof, and no breathability figure at all — on a bag whose whole design argument is the membrane it names.
Before ordering
Nothing on this page tells you whether it fits you or your mat. Those figures have to come from the maker’s own documentation, not from the listing.
Availability
The American Amazon store was listing it at about $170 at the time of writing.
Every figure here is what Keepa held on the day this page was last revised. Offers and prices shift without warning.
Prices quoted in this text were read on October 23, 2026. The live price is at the top of the page.
What it does well, and where it gives way
Strengths
Publishes two deniers, 30D over 40D, which is the construction the hub intro describes and nothing else here states
Names the membrane and its construction — Pertex Shield Diamond Fuse, 2.5 layer — rather than calling it a laminate
States bluesign approval for the shell, the floor and the mesh separately
Compromises
No weight and no packed size published, on a bivy whose name is about being light
No dimensions of any kind, so whether a body and a mat fit inside cannot be established
Waterproof is claimed with no millimeter figure, and breathability is not claimed at all
Where this model is listed
A listing is not an offer: the reference exists on these stores, availability changes daily.
Not published on the listing — the listing says waterproof and names the membrane, without a millimeter figure
Breathability figure
Not published on the listing
Breathability test named
Not published on the listing
Seam taping
Not published on the listing
Construction
Not published on the listing — the listing publishes materials only, with no pitched or cut dimensions and no mention of a pole
Entry and closure
Not published on the listing
Packed size
Not published on the listing
Weight
Not published on the listing
Amazon reference
B0BSKS163Z
EAN
0727602911472
What people ask before buying
What does 30D over a 40D floor tell you?
It is the construction the hub intro describes: a lighter canopy over a heavier floor, because the floor is what meets gravel. Publishing both numbers is rare here, and it is the one part of this listing that is fully answered.
Why does the most expensive bivy publish the least?
That is the finding, and it repeats across this niche. This listing gives a materials block and nothing else — no dimension, no weight, no packed size, no hydrostatic head. Price does not predict how much a maker publishes, and on this page it runs the other way.
Does Outdoor Research publish a hydrostatic head?
No. Not published on the listing — the listing says waterproof and names the membrane, without a millimeter figure. What the listing does publish instead is the fabric: Pertex Shield Diamond Fuse 2.5L, 100% nylon ripstop upper; 100% nylon floor with TPU lamination; 100% polyester mesh — stated, all bluesign approved.
Our score
7.8/ 10
A materials block without a product around it. Two deniers and a named membrane, and not one figure you could pack, pitch or fit yourself into.
The buyer this one serves, among camping gear
A buyer who knows this model already and is reading the listing for its fabric specification.
Sources
Specifications: the manufacturer sheet for camping and hiking gear and the matching Amazon product page. Prices and availability: Keepa. Every figure on this page names its source.
Emergency bag · sold as a pair · PE film with aluminum-coated inner · 213 × 91 cm (83.9 × 35.8 in) · 115 g stated · 120 dB whistle
An emergency survival bag sold in twos with a whistle sewn in — it names its film and gives a weight, and publishes nothing about breathability or closure.
Best for: A kit where a named material and a published weight are wanted from an emergency bag.
One-person bivy shelter · two aluminum poles · PU 5000 mm (196.9 in) flysheet · sealed and double-stitched seams · 215 × 75 × 61 cm (84.6 × 29.5 × 24 in) · 1.3 kg complete, stated
A poled one-person shelter sold as a bivy, publishing a flysheet water column, sealed seams and a complete-set weight — with no fabric named and no breathability figure.
Best for: A solo pitch where head room and a sealed floor matter more than packing small.
Sleeping-bag cover · 3-layer laminate · 5,000 mm (196.9 in) water column · breathable membrane, no figure · 225 × 85 cm (88.6 × 33.5 in) · 1,300 g and 40 × 8 cm (15.7 × 3.1 in) packed, stated
A generously cut laminate cover that publishes its water column, its packed size and its weight — and calls its membrane breathable without ever putting a number on it.
Best for: A cover bought for cut and closure rather than for weight, over a bulky synthetic sleeping bag.