Fenrir Expedition-Grade Down Jacket

£329.00

High-loft lightweight down jacket delivering our maximum warmth to weight performance.

850 Fill Power DownTek™ hydrophobic goose down with a 93/7 down/feather ratio. Pertex® Quantum Pro outer, made from 100% recycled fishing nets via Bureo® NetPlus®. 65g lighter for 2026, with narrower baffles, enhanced articulation and a redesigned hood. PFC-free DWR finish. Synthetic insulation at cuffs, collar and shoulders. Stuff sack included. What 850 fill power means in practice — and when to choose Fenrir — is in the details below.

Our ethical approach complies with the Responsible Down Standard. Our hydrophobic down uses bluesign®-approved clean chemistry.

Colour Black

Size Small

Sizing charts

The measurements in the charts refer to your body measurements. Measure your body as described and then choose the corresponding product size.

Men's Sizing

	Small EUR 46 - 50	Medium EUR 50 - 52	Large EUR 52 - 54	X Large EUR 54 - 56
Chest	96 - 102 cm 38 - 40 in.	102 - 106 cm 40 - 42 in.	106 - 111 cm 42 - 44 in.	111 - 116 cm 44 - 46 in.
Waist	76 - 81 cm 30 - 32 in.	81 - 86 cm 32 - 34 in.	86 - 91 cm 34 - 36 in.	91 - 96 cm 36 - 38 in.
Inside Leg	80 cm 31.5 in.	81 cm 31.9 in.	82 cm 32.2 in.	83 cm 32.7 in.

Women's Sizing

	X Small UK 6 - 8 EUR 34 - 36 US 2 - 4	Small UK 10 - 12 EUR 36 - 38 US 6 - 8	Medium UK 12 - 14 EUR 40 - 42 US 8 - 10	Large UK 14 - 16 EUR 42 - 44 US 10 - 12
Bust	82 - 86.5 cm 32 - 34 in.	86.5 - 91.5 cm 34 - 36 in.	91.5 - 96.5 cm 36 - 38 in.	96.5 - 101.5 cm 38 - 40 in.
Waist	64 - 68.5 cm 25 - 27 in.	68.5 - 73 cm 27 - 29 in.	73 - 77.5 cm 29 - 31 in.	77.5 - 82.5 cm 31 - 33 in.
Low Hip	88 - 92.5 cm 34.5 - 36.5 in.	92.5 - 97.5 cm 36.5 - 38.5 in.	97.5 - 102.5 cm 38.5 - 40.5 in.	102.5 - 107.5 cm 40.5 - 42.5 in.
Inside Leg	77 cm 30.3 in.	78 cm 30.7 in.	79 cm 31.1 in.	80 cm 31.5 in.

How to measure

Chest/Bust

With the tape under your armpit, measure across fullest part and across shoulder blades.

Waist

Measure around natural waistline at the narrowest part.

Low Hip

Measure around the widest part of the hip bones.

Inside leg

In a standing position, measure from top of inside leg at crotch to ankle bone.

Small Medium Large XL

UK shipping from £3.99. Next-day delivery available.

Fenrir Expedition-Grade Down Jacket

£329.00

Black Small

Use & Highlights

When to use — Cold weather insulation layer under a shell; capable as a standalone piece in cold but settled conditions; the warmest jacket in the Jöttnar range for its weight. Choose when weight matters most.

850 Fill Power — what it means — 850 is expedition grade: each ounce of down occupies more loft space and traps more air than lower-rated fills. Combined with a 93/7 down-to-feather ratio, this is as close to pure loft as a down jacket gets. The 2026 update adds narrower baffles for improved warmth and compressibility.

Hydrophobic down — DownTek™ treatment bonds to each filament at a molecular level — the down retains warmth when damp rather than collapsing. Stays dry 10x longer and dries 3x faster than untreated down.

NetPlus® outer — Pertex® Quantum Pro 30D outer woven from Bureo® NetPlus® reclaimed fishing nets — fully traceable to source and a more demanding standard than standard recycled nylon.Windproof and highly water-resistant. PFC-free DWR finish.
Synthetic reinforcement zones — 100g/m² synthetic insulation at the cuffs, collar and shoulders — the zones most exposed to moisture and compression that compromise down performance.

Hood — Down-filled hood adds warmth at the head and neck. Adjustable with a glove-compatible concealed cord. Redesigned for 2026.

Weight & packability — 65g lighter for 2026. Stows into separate stuff sack.

Ethics & sustainability — Responsible Down Standard compliant. DownTek™ treatment uses bluesign®-approved clean chemistry. Outer woven from Bureo® NetPlus® reclaimed fishing nets.

Tech Specs & Care

Outer fabric
Pertex® Quantum Pro 41gsm
30D micro ripstop
Bureo® NetPlus® 100% recycled fishing net nylon
PFC-free DWR finish

Fill
850 Fill Power DownTek™ hydrophobic goose down
93/7 down/feather ratio
Stays dry 10x longer, dries 3x faster than untreated down
Synthetic reinforcement
100g/m² synthetic insulation at cuffs, collar and shoulders

Hood
Down-filled, redesigned 2026
Glove-compatible concealed cord adjuster
Added peak

Cuffs
Technical stretch cuffs

Draw cords
Anti-snag hem cords

Pockets
2 × insulated hand warmer pockets
1 × internal zipped valuables pocket

Weight & fit
410g (men's medium inc. stuff sack). 65g lighter for 2026 vs previous version
Narrower baffles, enhanced articulation

Stuff sack
Separate stuff sack included

Care
Machine wash 30°C — gentle wash
Tumble dry cool
Do not dry clean, do not iron, do not bleach

Fantastic quality; slightly tricky fit

The jacket is excellent quality; lightweight and the waterproofing seems pretty good so far.

The down is quite thin and I must admit I was expecting it to be a slightly heavier weight, but given the thickness it does seem quite warm (similar when comparing this to my old Icebreaker down jacket that had merino fill).

My main 'issue' is the fit. These jackets all seem to favour 'thin' builds. I am a 44" chest, 32" waist and just over 6ft tall. A large is too tight on the chest, and the XL I have to cinch quite a lot to get it to 'seal' at the bottom and keep in the warmth. It isn't a problem unique to Jottnar, but I had been hoping it might be one they had catered for.

All that said, I am very happy with the purchase.

Toasty!

I bought this jacket for a trip to Finland in winter and even though this is a lightweight jacket it was plenty toasty for the -5° to -10° we were experiencing. Beautifully made with plenty of great details.

Superb quality

Well impressed with the product that is well put together. I did a lot of research prior to placing an order with Jottnar. Very pleased with the product. If in doubt, BUY!!

Great bit of kit

Just what I needed, jacket where I can just wear a t shirt under, would purchase more of this brand, highly recommend

Beats the big names

First jacket from these guys replacing a very well worn Rab (8-9 years old).
Typically have defaulted to Arc for costs but the last few years there’s been such a decline in their quality.
Fit wise, a medium for me was spot on. 6”2, 39” chest, 33” waist.
Subtle features especially in the cuff are brilliant. Additionally the water resistance has held up even when strong winds present too.
Very hard to fault the jacket at all in fact.
You’ve got a new loyal customer for sure

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About Jöttnar

Pro Team

Fenrir Expedition-Grade Down Jacket

Sizing charts

Fenrir Expedition-Grade Down Jacket

Customer Reviews

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