Search Search
5.0 8

Sea to Summit

Trek TkIII Sleeping Bag (-11°)

Sorry! We're unable to get our hands on any more of these.

From $265.00

Delivery estimate to:

Check instore stock View all delivery info

Pickup from our store

92 Richmond Rd, Keswick SA Mon - Fri: 9am - 5.30pm
Sat: 9am - 5pm
Sun: 12pm - 5pm
17 Doherty St, Brendale QLD Mon - Fri: 9am - 5.30pm
Sat: 9am - 5pm
Sun: 9.30am - 2.30pm
Sea to Summit Trek Series Sleeping Bag Watch video

The warmest bag in the Sea to Summit Trek range of sleeping bags, the Tk3 is a bag for those with a wider frame not wanting to resort to a more restrictive mummy shaped bag. Packing down to 5L, it’ll fit neatly in the bottom of most trekking packs.  

The bag incorporates highly-breathable 2D PermaShell™ fabric which will keep your down in tip top shape. The tapered rectangle design makes the Trek ideal for people with a larger frame or slickers for space. The full length side and foot zips mean you can zip it wide open and use it as a quilt, for those warm nights or if you have company. A two-dimensional hood is useful for trapping extra warmth on those colder nights.

An oversize internal pocket is big enough to keep your wallet, passport, and iGadget. The lightweight Ultra-Sil® compression bag compresses the bag down to a mere 7L. The Trek Tk1 is a bag for the trekker wanting a freer night sleep, but with the warmth to get them through a cold night in the hut.

  • Comfort rating -1⁰c
  • 650+ loft 85/15 premium duck down
  • Breathable 2D PermaShell™ fabric
  • Tapered rectangular design
  • Oversized internal zippered pocket
  • Lightweight Ultra-Sil® compression bag, mesh storage cell and laundry bag included
Snowys Code:
Supplier Code:
Comfort Temp. Rating:
-5 °C
Lower Temp. Limit:
-11 °C
Max. User Height:
170 cm
Internal Girth:
148 cm Chest |146 cm Hip |98 cm Foot
External Dimensions:
170L x 74W x 5H cm
Packed Dimensions:
37L x 21W x 20.5H cm
Compressed Volume:
7.05 L
33D Nylon with DWR 342T
Fill Material:
650+ Loft 85/15 Premium Duck Down
Fill Weight:
700 g
40D Nylon 310T
Zip Draft Tube:
Double YKK #5
1.215 Kg
Suggested Use:
Camping | Hiking
Limited Lifetime

(8 reviews)
5.0 8
5 stars
4 stars
3 stars
2 stars
1 star
Jun 07 2017


Hands down the best sleeping bag!!! You will not regret buying this.

- Sydney
Apr 02 2017


Bought this bag for tassie hikes, primarily hikes in the mountains.
Tried and tested in temps around -2. With merino thermals found it was a little too warm, had to open it up. Very happy with it.

- Tassie
Feb 15 2017

Warm as toast

I absolutely LOVE this bag! As an older person I feel the cold so appreciate being surrounded by fluffy duck feathers, nicely lofted, on cold nights camping. Perfect shape too- I don't like being "mummified"!

- Bunbury, WA
Feb 03 2017

Brilliant winter bag

Service was first rate for purchase. This bag is really awesome and well thought out. For hikes is a little large but still fits in bottom of 75l backpack ok. Partner got the Trek II and if you are using for general use that would do fine. Gets too hot for Aussie summers.

Look forward to using it in Nepal!

- Longwarry
Jan 14 2017

Great bag

Prompt service, fast delivery.
Great bag ( I am 183cm) very warm and comfortable.

- Adelaide
Oct 05 2016

Quality Aussie bag

So happy I spent a little extra and purchased the warmer tklll, Even when the temp reached around 7 degrees Celsius I simply opened up the bottom and it was comfortable. The width/length is great for my wide build 6'2 body. Packs easily away into a small size.

- Perth
May 27 2016

Great product

Purchase and delivery was excellent. We bought two of these sleeping bags. First night of using them it was at 1300 metres in Victorian High Country, A cold wet stormy night and we were warm and slept well. Highly recommend the product.

Jun 25 2015


This sleeping bag has very high quality in every area. Nothing to complain. It's just perfect for me in winter. The price at Snowy is the best I found in Aust. The delivery was faster than I expected. It's like someone done the shopping for you and delivered to your door in a flash. I am fully satisfied. It's excellent experience to shop at Snowys.


Dimensions when stuffed in the stuff sack?1 answer

The "Packed Size" dimensions don't seem to agree with the compressed volume of 7.5 L -- they correspond to about 12.5 L if you assume it's a cylinder. Do you know the rough dimensions when it's compressed in its stuff sack? For the "long" size please. Cheers, Tom

- Perth(1 year ago)

G'day Tom, 

For consistency we go by Sea to Summits compressed size, which is measured by the standard test method for measuring the volume of sleeping bags (ATSM F1853-11).

I've just double checked the specs provided by the supplier, and it says that the Trek TkIII long it’s going to be 7.05L compressed. The dimensions of the bag compressed will probably depend on how much force you use to compress it, so it’s hard to give a black and white answer there unfortunately. 

- Snowys(1 year ago)

My new sleeping bag has a damp odour 1 answer

Is this sleeping bag faulty?

- Thornbury(1 year ago)

G'day Robert, 

I've just had a chat to our warranties manager and they've said that we haven't had an issue with a damp smell for any of the Sea to Summit sleeping bags, so I'm not too sure how that could happen unless it somehow got wet in transit. 

Down will have a slight odour as it's a natural product, so firstly we would suggest airing out the bag in a well-ventilated area, and if you still feel that there is a damp odour - give us a call on 1300 914 007 and we'll look into it further for you Robert. 

- Snowys(1 year ago)

temperature trek III1 answer

Is the sleeping bag Trek III still comfortable to be used in the summer at 15 ° C

- -(1 year ago)

G’day Stijn,

The Seat to Summit Trek TkIII is the warmest in their Trek range and it has a comfort rating of -5 degrees so it is designed for Autumn/Winter weather.

I would say that if you’re cold at home on a 15° night, then chances are you’d want a bag that was on the warmer side like the TkIII. If you’re a hot sleeper you might want to consider the TkII as that has a -1 ° rating.

As far as we know there aren’t any bags that are designed to be used in Summer and Winter, but in general it’s better to be a little too warm and unzip your bag, then be too cold and not be able to do anything about it when you’re out in the elements.

- Snowys(1 year ago)

Would this bag be suitable for a smaller framed man? 1 answer

This range talks about being suited for larger framed men but im wondering whether it would be suitable for someone smaller such as myself? I like the idea of a little more room but would too much heat be wasted? Id be using it in places where the temperature would never drop below -5°C. Thanks.

- BURNIE, TAS(1 year ago)
When we refer to space for a wider frame, we are really comparing it to the mummy shaped bags which are very restrictive. If you are not a particularly cold sleeper, then this bag will be suitable for you. It has suitable drawstrings in place so you can wrap yourself up in the bag and trap all the warm air, and it provides versatility in its temperature range across warm and cold temperatures. Furthermore, by adding a thermal liner you can make the bag even warmer for mid winter expeditions.
- Snowys(1 year ago)

sea to summit trek111 bag1 answer

Under details it states the comfort rating is -1. Is it -1 or -11?

- BENTLEIGH EAST, VIC(1 year ago)
Hi Kim, this sleeping bag has a comfort rating of -5 and a lower limit of -11. Sorry for the confusion, I'll get the fixed in the product description.
- Snowys(1 year ago)

Trek II or Trek III?1 answer

I'm deciding between the Trek 2 and 3. Trek 3 is about 200g more than Trek 2. Would that make much of a difference when hiking in terms of space and weight overall? Also, I'd like to use it for camping out in country and/or alpine areas during June and July, would the Trek 2 still be sufficient for the colder nights or will the Trek 3 be a better option if temperatures are freezing or below?

- St Kilda(2 years ago)
The difference in packed size between the two will be negligible Hannah, and it really depends on how you look at the 200 g of extra weight. There is no point in getting a cooler bag and end up throwing 200+ grams of extra clothing in to compensate, you might as well get the benefit of lightweight down in the warmer option. I would recommend the Trek 3 for alpine use also. These have a relaxed shape and will not be as efficient as a mummy bag such as the Talus, so more down is better. This shape has its benefits in warmer climates though... there is always a trade off.
- Snowys(2 years ago)
is initializing