Ultra Down Pullover: K Series

Our lightest sub-zero down pullover. A 'K Series' product. Warmth to weight at the limit of possibilities for extra-keen lightweight backpackers and mountain racers.
Typical Operating Temperature
Guideline minimum temperature. Sleeping Bag TOT: you should get a night’s sleep, under normal circumstances. Clothing TOT: you should feel warm enough, assuming low/moderate activity. Sleep System TOT: relates to full system. For more details, see our Technical Briefing.
-5°C / 23°F
For clothing, weight is for size: M. For sleeping bags, weight changes with selected length/width. N.B. there may be some variation in the weights of finished products.
225g / 8oz
Ultra Down Pullover: 'K Series'

Ultra's extremely low weight and bulk make it perfect for backpacking.
Judy Armstrong, TGO Magazine ("Lightest in Test").



  • A PHD K Series product: Ultimate warmth / weight performance
  • PHD's Unique 1000 fillpower down
  • Water-resistant Ultrashell outer fabric
  • Superlight 10X inner fabric
  • Stitch-through construction for lightness
  • Full width front hand-warmer pocket
  • Small zipped security pocket
  • Short lightweight front zip - pullover style
  • Drop-tail back
  • Elasticated side hem
  • Cuffs: Light Lycra
  • Stuff sac
  • Option:
    • Stud-on superlight hood
  • Pack size: 10 x 18cm*

*Please note: We make our stuff sacs big enough to allow fairly easy stuffing rather than reducing the jacket to the tightest minimum.


This K Series product has been created for one single reason, to take warmth-for-weight performance to the limit of what's possible. Unique 1000 down, super-light materials, and specific design features mean that the word Ultralight now applies to this wide range of gear that will take you to the Poles as well as on a Sahara Marathon. More on the K Series...

Also available in custom sizes. We make clothing to order, so if you’re not a standard size we can make it to fit. To order a non-standard custom size, select the Custom Sizing tab, choose your body width, and then the body/arm lengths, shorter or longer, that work for you. A custom size takes us a little longer (typically two weeks longer) to make and, because it’s personalized, it’s non-returnable and our customer loyalty scheme can’t be applied.

Our original Ultra Pullover won accolades as "the ultimate down jacket for ultralight backpacking". Unbelievably this K Series Ultra Pullover weighs less despite the addition of a water-resistant outer fabric. This is thanks to our unique 1000 down and the new ultralight 10X fabric inner.

Pared down design as for all the Ultra range, elastic at side-waist, Lycra cuffs, through front pocket with concealed security pocket, and drop-tail back.

TGO magazine recommendedTGO Magazine "Lightest in Test"

Backpacking Light - Highly RecommendedBackpacking Light "Highly Recommended"

Ultrashell (weight: 40 gsm)

One of the lightest of PHD's coated materials. This ripstop nylon provides complete wind block and good water resistance at minimal weight. Ultrashell gives an excellent upgrade to performance with very little weight penalty.

Ultralight 10X fabric (weight: 26 gsm)

10X, PHD's first 10 Denier Fabric. 9,000 metres of the yarn used to weave 10X weighs just 10g, that's about the same as a £1 coin! For all its thinness 10X is amazingly downproof and with reasonable care will go on giving you good service for years.

1000 fillpower down

This rarest of all downs we reserve for the K Series. European goose down of unique quality. 1000 provides the highest warmth-for-weight performance possible from down. More on our down insulation.

"I used this as my warm layer on the John Muir Trail. I had a hood-less sleeping quilt, a PHD K series pullover without the hood and a separate sleeping bag hood. This combination was perfect for lightness, warmth and flexibility. The PHD pullover was fantastic since it was so light it was no hassle to carry. When I did need it, it proved to be extremely warm for its weight. Originally I bought a 'featherlight' jacket from a well recognised brand but the (fashionable) baffles were small and the net result was that the jacket just wasn't very warm since the down had no room to loft. I sold that jacket and contacted PHD who were really helpful. The weight is comparable to the trendy jacket but it is MUCH warmer. The loft on the jacket is excellent and the fabric is very bleed-proof for the weight. Every night I had to check my ultralight sleeping bag (not from PHD!) for down bleed but I stopped bothering with the PHD pullover – there just wasn’t any bleed."
Nick Freeman

"Both for summer Alpine and winter UK I always carry a 'get out of trouble' layer, which usually resides in the bottom of my rucksack. I need it to be reliably warm, but at the same time light and compact. PHD's Ultra Down Pullover hits this particular nail on the head for me, delivering a solid -5° C rating, whilst at the same time packing to about the size of an orange and weighing less than 230g. It's part of the K Series range of garments that utilise superlight fabrics and 1000 fill power down to deliver an extremely light but reliable garment"
Trail Magazine's Mountaineering editor, Jeremy Ashcroft

The reviews below relate to the previous version of this pullover, which weighed the same but didn't have a proofed outer fabric

TGO magazine recommended

"Ultra's extremely low weight and bulk make it perfect for backpacking ... The combination of warmth ... weight and water resistance is wonderful."
Judy Armstrong, TGO Magazine ("Lightest in Test").

Backpacking Light - Highly recommended

"If I were to list my specifications for the perfect ultralight down jacket, it would describe the PHD Ultra Down Pullover exactly ... One trip with this jacket is all it took to convince me that it is the ultimate down jacket for ultralight three-season backpacking in the mountains, winter backpacking in the desert, or cold (but not frigid) weather pursuits of any kind ... Based on its fit and exceptional loft and warmth for its weight, the PHD Ultra Down Pullover is my new favorite jacket."
Will Rietveld, Backpacking Light ("Highly Recommended"). Read full review.

"The uber light Ultra Down pullover is simply brilliantly designed, with astonishing attention to detail. It fits perfectly with very little wasted in the way of tensioners, cinch cords and elastic, an amazing feat. Surpisingly for something as light as this, it is tough and won't fall by the wayside when the weather and terrain hits you hard."
Richard H.

"I am delighted with it. It really is a ridiculously light bundle of warmth that packs down to nothing. I had considered buying the patagonia special edition down sweater, but I'm very pleased that I went for the Ultra instead. - I'm pretty sure it's going to spend most of its life in my rucksack - If I can manage to prise it from my wife's hands!"
Chris W.

"I loved it from the off. It's madly warm for its weight. It's become my insulating layer of choice."
Dave Hanlon.

"Very impressed with the warmth to weight ratio."
Sergeant in Devon & Cornwall Constabulary.

"Thank you for the swift making and delivery of my ultra down pullover. It is an absolutely beautiful coat, and I am extremely grateful of the effort you have put in to get the coat ready before I start my expedition at the end of this month. I can assure you that this will not be my last purchase from you."
Dan Morley.

"Absolutely Fantastic !!!!!!!!!!!"
Ray Griffiths.

"It's a fantastic garment."
Phyllida Poltock.

"Really delighted with the product to date."
Mark Alexander.

"I recently bought an Ultra Pullover from you. I used it in the lakes before Xmas in conjunction with a pied elephant sleeping bag to bivvi out. Was really impressed as the weather turned out rather horrible and I got a fair bit of condensation in my bivvi bag. I thought the down would get wet quick but that didn't happen - so I stayed just warm enough. All in all pretty amazing from something so small and light - had just 2 layers underneath. So I've been really impressed and want to say thanks. I will be spreading the word about your products."
Brian Leite.

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