Alpine Guest Letu Ultralight Down Bag — 10D/7D Nylon, 95% 800+FP Down, 655 g to 1.6 kg, Three Lengths

Alpine Guest Letu Ultralight Down Bag — 10D/7D Nylon, 95% 800+FP Down, 655 g to 1.6 kg, Three Lengths

M · 210 cm / Winter / Black
$899.00 AUD
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Alpine Guest Letu Ultralight Down Bag — 10D/7D Nylon, 95% 800+FP Down, 655 g to 1.6 kg, Three Lengths
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  • Alpine Guest Letu Ultralight Down Bag — 10D/7D Nylon, 95% 800+FP Down, 655 g to 1.6 kg, Three Lengths
  • Alpine Guest Letu Ultralight Down Bag — 10D/7D Nylon, 95% 800+FP Down, 655 g to 1.6 kg, Three Lengths
  • Alpine Guest Letu Ultralight Down Bag — 10D/7D Nylon, 95% 800+FP Down, 655 g to 1.6 kg, Three Lengths
  • Alpine Guest Letu Ultralight Down Bag — 10D/7D Nylon, 95% 800+FP Down, 655 g to 1.6 kg, Three Lengths
  • Alpine Guest Letu Ultralight Down Bag — 10D/7D Nylon, 95% 800+FP Down, 655 g to 1.6 kg, Three Lengths
  • Alpine Guest Letu Ultralight Down Bag — 10D/7D Nylon, 95% 800+FP Down, 655 g to 1.6 kg, Three Lengths
Alpine Guest Letu Ultralight Down Bag — 10D/7D Nylon, 95% 800+FP Down, 655 g to 1.6 kg, Three Lengths

Down Sleeping Bag Alpine Guest Letu Ultralight Down Bag

Our lightest bags: 800-plus-fill down in a 10D shell and 7D lining, in three lengths and four warmths.

$899.00 AUD
Down
410–1,330 g, 800+FP
Bag weight
655 g–1.6 kg
Shell
10D / 7D
Full specification
Size
Warmth
Colour
  • Tracked delivery Australia-wide, A$19.95 on orders from A$100 (A$9.95 under): 1–3 business days to dispatch, then 10–20 business days on the way. Order a month before your trip. Shipping
  • 30-day returns. We pay the postage if it's faulty or not as described. Returns
  • Every figure on this page is the maker's own or our clearly labelled guide. No made-up lab ratings.

The Alpine Guest Letu is an ultralight mummy bag with 95% white duck down (stated 800+ fill power) in a 10D water-repellent shell and 7D lining. Three lengths and four warmths, from 410 g of down in a 655 g bag to 1,330 g in a 1.62 kg winter bag.

The weight of a premium bag, for a lot less.

Best for
Lightweight hikers, multi-day walks and anyone who counts grams.
Think twice if
Featherweight fabrics need care around sharp gear and sparks. If you're hard on gear, the 20D Black Snow 800FP Mummy is tougher.

  • From 655 g

    The summer model weighs less than a litre of water.

  • 10D shell, 7D lining

    Fine, featherlight fabrics that let the down loft fully.

  • Three lengths

    S, M or L, so shorter hikers don't carry empty bag.

Warm enough for your trip?

Plan on the “warm to” figure: our own cautious guide, or the maker's comfort rating where that's what we quote. If you sleep cold, or you're not sure, add 5°C. And if you're torn between two bags, take the warmer one: a bag that's too warm, you unzip; one that's too cold, you can't fix at 2 am.

Compare it with every bag we sell
  • Letu M 450 g Comfortable to about 7°C If you sleep cold, about 12°C
  • Letu M 700 g Comfortable to about 1°C If you sleep cold, about 6°C
  • Letu M 950 g Comfortable to about −4°C If you sleep cold, about 1°C
  • Letu M 1200 g Comfortable to about −8°C If you sleep cold, about −3°C

Is it the right bag for your trip?

Pick the coldest night you expect. We'll show every bag and quilt that's warm enough, lightest first, and mark this one if it makes the cut.

How cold will your coldest night be?
  1. UL250 Warm to 15°C 250 g A$249
  2. Quilt 260 g Warm to 12°C 260 g A$329
  3. 10D goose 400 g Warm to 8°C 400 g A$369
  4. 95% envelope 400 g Warm to 10°C 400 g A$259
  5. Black Snow 400 g Warm to 8°C 400 g A$239
  6. Cozy 300 Warm to 3°C 400 g A$299
  7. Envelope 400 g Warm to 10°C 400 g A$229
  8. Long 225 cm 400 g Warm to 8°C 400 g A$319
  9. Mummy 400 g Warm to 8°C 400 g A$259
  10. Oversized 400 g Warm to 8°C 400 g A$249
  11. Letu M 450 gThis bag Warm to 7°C 450 g A$599
  12. Quilt 500 g Warm to 5°C 500 g A$449
  13. 95% envelope 600 g Warm to 5°C 600 g A$289
  14. Envelope 600 g Warm to 5°C 600 g A$259
  15. Mummy 600 g Warm to 3°C 600 g A$289
  16. Oversized 600 g Warm to 3°C 600 g A$279
  17. Winter envelope 600 g Warm to 5°C 600 g A$249
  18. Cozy 600 Warm to 1°C 630 g A$329
  19. 10D goose 700 g Warm to 2°C 700 g A$449
  20. Black Snow 700 g Warm to 2°C 700 g A$279
  21. Letu M 700 gThis bag Warm to 1°C 700 g A$729
  22. Long 225 cm 700 g Warm to 2°C 700 g A$369
  23. 95% envelope 800 g Warm to 1°C 800 g A$329
  24. Mummy 800 g Warm to −1°C 800 g A$329
  25. Oversized 800 g Warm to −1°C 800 g A$319
  26. Winter envelope 800 g Warm to 1°C 800 g A$269
  27. Letu M 950 gThis bag Warm to −4°C 950 g A$819
  28. 10D goose 1000 g Warm to −5°C 1,000 g A$549
  29. 95% envelope 1000 g Warm to −2°C 1,000 g A$359
  30. AM1000 Warm to −3°C 1,000 g A$279
  31. Black Snow 1000 g Warm to −5°C 1,000 g A$329
  32. Long 225 cm 1000 g Warm to −5°C 1,000 g A$439
  33. Mummy 1000 g Warm to −5°C 1,000 g A$369
  34. Oversized 1000 g Warm to −5°C 1,000 g A$359
  35. Winter envelope 1000 g Warm to −2°C 1,000 g A$299
  36. 95% envelope 1200 g Warm to −4°C 1,200 g A$399
  37. Letu M 1200 gThis bag Warm to −8°C 1,200 g A$899
  38. Mummy 1200 g Warm to −8°C 1,200 g A$399
  39. Oversized 1200 g Warm to −8°C 1,200 g A$399
  40. 10D goose 1300 g Warm to −9°C 1,300 g A$649
  41. Black Snow 1300 g Warm to −9°C 1,300 g A$379
  42. Long 225 cm 1300 g Warm to −9°C 1,300 g A$499
  43. Extreme 1,500 g Warm to −10°C 1,500 g A$339
  44. Double 1,800 g Warm to 3°C 1,800 g A$549
  45. Double 2,000 g Warm to 1°C 2,000 g A$579
  46. Extreme 2,000 g Warm to −13°C 2,000 g A$379

of our bags and fill weights will keep you warm enough. Lightest first, so the top one is the lightest that will do the job.

Read the full guide: trips, safety and what else to pack

  • Plan for the coldest night

    Hills, valleys and inland camps get much colder than the forecast for the nearest town. Check the overnight low for where you'll actually sleep.

  • If in doubt, go warmer

    Being too cold at night isn't just a bad night's sleep. A long, cold night in a bag that's too thin can tip into hypothermia, and there's no fixing it at 2 am.

  • The mat matters as much as the bag

    Down underneath you is crushed flat, so the ground steals your heat. Below freezing, use an insulated mat with an R-value of 4 or more.

  • Help the bag help you

    Change into dry clothes, eat something before bed, and wear a beanie. A bag holds warmth in, but it can't make it.

Which one?

WarmthS · 195 cmM · 210 cmL · 225 cm
Summer410 g / 655 g450 g / 705 g500 g / 780 g
Three-season640 g / 885 g700 g / 955 g780 g / 1,060 g
Cold nights860 g / 1,115 g950 g / 1,215 g1,050 g / 1,340 g
Winter1,090 g / 1,345 g1,200 g / 1,465 g1,330 g / 1,620 g

Each cell is grams of down / whole-bag weight (maker's figures).

Where it sits among every bag we sell, by grams of down

Choose by your coldest night

Highlighted: Letu M 450 g (450 g), Letu M 700 g (700 g), Letu M 950 g (950 g), Letu M 1200 g (1,200 g). The other marks are our other bags and fill weights.

The numbers

Taken from the maker's own listing and spec cards for this exact model; anything marked our guide is ours. Where the maker doesn't publish something, the line is left out rather than guessed.

Down95% white duck down, stated 800+ fill power (maker's figures, not independently tested)
Shell and lining10D tear-resistant nylon with a water-repellent finish; 7D ultralight nylon lining
LengthsS 195 × 78 cm (people under 173 cm)
M 210 × 80 cm (173 to 185 cm)
L 225 × 85 cm (over 185 cm)
Fill and weight, MSummer: 450 g of down, 705 g bag
Three-season: 700 g of down, 955 g bag
Cold nights: 950 g of down, 1,215 g bag
Winter: 1,200 g of down, 1,465 g bag
Comfortable to (our guide)Summer: about +7°C
Three-season: about +1°C
Cold nights: about −4°C
Winter: about −8°C
Maker's comfort figuresSummer 2°C, three-season −6°C, cold −14°C, winter −22°C. We think these are optimistic and don't use them.
DetailsTwo-way zip, draught tube, shaped hood and footbox; a left and a right bag join together

“Warm to” is the figure we'd plan on: our own cautious guide, or the maker's comfort rating where that's what the table quotes. About the temperatures: Our guide, not a lab rating. It is set on the cautious side because nobody has lab-tested this down. Brands like Sea to Summit pay for an independent EN/ISO 23537 test; nobody has done that for this bag, and we won't pretend otherwise. So compare on grams of down and bag weight first: they're physical quantities. How to read them

Complete your sleep system

A bag is half of a warm night. Here's what else makes it work, and what people usually add.

  • Inflatable Sleeping Pad With Pillow — Built-In Foot Pump, 190 × 60 cm, About 600 g
    Inflatable Pad With Pillow

    A cushioned air pad with its own pillow and a built-in pump. No puffing, no separate pillow to pack.

  • Ultralight Sleeping Bag Liner — Keeps Your Bag Clean, Adds a Little Warmth, Packs to a Fist
    Ultralight Sleeping Bag Liner

    The cheapest way to make a down bag last longer: sleep in this, wash this.

  • Roll-Top Dry Bag Set of 5 — 1.5, 2.5, 3.5, 4.5 and 6 L, Buckle Closure
    Dry Bag Set of 5

    Five small roll-top bags that keep the important things dry and easy to find.

  • Trekking Pole Tent 1–2 Person — 1.38 kg, Two Doors, 15 cm Bathtub Floor, PU 2000 mm
    Trekking Pole Tent 1–2P

    A double-door A-frame that uses your trekking poles as its frame, so there are no tent poles to carry.

A mat rated for the season

The ground takes more heat than the air, and down underneath you is crushed flat. As a rough guide: an R-value of about 2 for summer, 3 to 4 for three seasons, and 5 or more on snow.

A way to keep it dry

Wet down stops insulating. Pack the bag in its compression sack inside a dry bag or pack liner, and air it out when you reach camp.

Questions

Which length do I need?
S for people under about 173 cm, M for 173 to 185 cm, L above 185 cm. A bag that fits closely is warmer; one that's too short crushes the footbox.
Which warmth?
Summer to about +7°C, three-season to about +1°C, cold nights to about −4°C and winter to about −8°C (our guide, M size). Go one step warmer if you sleep cold.
How do I store it?
Travel in the compression sack, but store it loose at home (a big cotton bag, or hanging) so the down keeps its loft.
Which size should I buy?
As a rule, pick a bag at least 15 cm longer than you are, so your feet don't press into the down and make a cold spot. The spec table above gives the length, or the height the maker says it fits. If you're between sizes, or like to sleep with a water bottle or clothes inside, go up.
Are the temperature ratings lab-tested?
No. Each temperature on this site is either the maker's own figure, labelled maker, or our own cautious guide, labelled our guide. None of these bags has an independent EN/ISO 23537 lab report, so we lead with fill weight and bag weight: physical quantities you can compare. Treat any temperature as a starting point and allow a margin, especially if you sleep cold.
Comfort, limit, extreme: which one do I use?
Comfort is the temperature a cold sleeper stays comfortable at; limit is where a warm sleeper, curled up, still sleeps. Extreme is survival only: never plan on it. Most people should plan on the comfort figure, and on a warmer mat than they think they need.
How do I store and wash a down bag?
Store it loose in its storage sack, not squashed in the compression sack. Wash it rarely, with a down-specific wash on a gentle cycle in a front loader, then tumble dry on low with two clean tennis balls until no clumps are left. It can take a few hours. A liner means you'll wash the bag far less often.
When will it arrive?
We dispatch in 1–3 business days, then it's 10–20 business days on the way to Australia. There's no warehouse or shopfront in between, which is why it takes longer and costs less. If you have a trip booked, order at least four weeks before you leave. You'll get a tracking number by email when the parcel is scanned. Full details on the Shipping page.
Will my order arrive in one parcel?
Gear from the same maker usually travels together. If your order has gear from more than one maker, it can arrive in two or three parcels, sometimes a few days apart. You'll get an email with a tracking number for every parcel, so you always know what's on the way.
Will I pay duty or GST on delivery?
No. Orders under A$1,000 clear into Australia without additional duty or GST, so there's nothing to pay when your parcel arrives.
What if it isn't right?
You have 30 days from delivery to return it unused and in its packaging. If it's faulty or doesn't match what we published, we pay the return postage and refund in full. See Returns.

More from this shelf

  • Tracked delivery Australia-wideA$9.95 on orders under A$100, A$19.95 from A$100. No duty or GST to pay on delivery.
  • Every number publishedGrams of down and weight on every bag, the R-value wherever the maker publishes one, capacity and weight on every pot, and a note wherever the maker's figures are unclear.
  • 30-day returnsUnused and in its packaging. We pay the postage if anything is faulty or not as described.
  • Replies within 24 hoursEmail us Monday to Friday and a person answers, not a bot or a call centre.