Rondoy Down Trousers

Our lightest big mountain and high-altitude trekking down-filled trousers. Now also available in custom sizes.
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.
-20°C / -4°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.
400g / 14oz
Rondoy Down Trousers - front showing reinforced knees

The lightest 'big mountain' down legwear that PHD has produced. They use 950 fill down, water-resistant Ultrashell face material and have full-length side-zips for ease of use. Serious cold weather trousers.
OutdoorsMagic Review



  • Rare 950 fill-power European pure goose down
  • Outer fabric: Water-resistant Ultrashell. An excellent balance of weight, water-resistance and breathability
  • Inner fabric: Superlight MX.
  • Box-wall construction for maximum loft
  • Side Zips:
    • Full length
    • Two way (join at the top)
    • Insulated under-baffle
  • Waterproof HS2 fabric reinforcement on the knees and the bum
  • Elasticated waist with adjustable shock cord hem
  • Stuff sac. Packed size: 17 x 28cm*


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


These down trousers/pants are now also available in custom sizesSpecify Waist and Inside Leg sizes independently to order made-to-measure down trousers/pants. This tailor-made service can cope with sizes from XXXS to XXXL and is ideal if your waist to inside leg ratio differs from standard, ready-to-wear patterns. 

High performance mountaineering trousers. Rated at -20ºC these trousers are ideal for 6000m peaks and high altitude trekking expeditions. Filled with exceptional 950 fill-power down, and made in our lightweight water resistant Ultrashell fabric, the full-length side zips and the added protection of waterproof HS2 on the knee and the seat make for a robust and superlight package.

Please note: If you order a custom-sized version of these trousers they will take longer (approximately 45 days) to be manufactured ready for dispatch. Custom-sized versions of these trousers are not returnable and customer loyalty discount cannot be applied.


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.

Superlight MX fabric (weight: 32 gsm)

A mini-ripstop nylon with excellent tear strength, MX is the pick of the superfine 15 denier downproof materials. We have tested lighter fabrics, but most have had significant drawbacks, while our confidence in MX is based on several years of extensive use in both our ultralight and our high mountain gear.

950 fillpower down

A newcomer to our range. European goose of rare quality. A high value alternative at the top levels of performance. More on our down insulation.

Waterproof HS2 outer fabric (weight: 88 gsm)

HS2 is PHD's high-spec 2-layer ripstop for waterproof outers on our down. It is light enough to be the optional taped shell on our sleeping bags and tough enough for expedition use in our Omega clothing. HS2 is completely waterproof (when the seams are taped) and offers excellent breathability.

"Using PHD gear has been a voyage of discovery for me, lighter than anything else I've used."
Peter McFarlane, a.k.a 'Petesy'

"PHD are at the forefront of down clothing technology. I researched long and hard before deciding what to buy, and this firm is world class."
Lord Forsyth, former Secretary of State for Scotland.

Works well with
From 684.21 620g -20℃
A lightweight mountaineers' and trekkers' Jacket for the 6000m Himalayan peaks,...
From 856.10 1040g -21℃
Mountain lightweight for low temperatures and high peaks. Ideal for fast ascents and...
From 180.76 170g
High-altitude expedition socks. Light, compressible and comfortable. For warmth in high...