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Sea to Summit

Basecamp Bt4 Sleeping Bag

From $379.90
or 4 easy payments of $94.98 with

Delivery estimate to:

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

You can sleep all through the night even in frosty conditions with the Sea to Summit Basecamp Bt4 Sleeping Bag. This model takes everything you love about the traditional Basecamp sleeping bag range, but swaps out down for synthetic which makes it perfect for adventurers who want full features, without the strain on your wallet.  

Insulated with Sea to Summit’s Thermolite fibre, you can be more carefree with this bag, as the synthetic fill makes it easier to clean and take care of. One of the most charmingly versatile sleeping bags on the market, Sea to Summit have added every feature to ensure you can use this bag in all weather conditions.

The clever design lets you adjust the bag to your preferred sleeping arrangement – so you can unzip the side for temperature control, unzip both sides to use it as a quilt with a closed footbox, or you can have your feet hanging out while staying completely zipped up. You can also use it with both sides undone like you would at home in your own bed, or remove the top for very warm evenings. If you’re travelling light, just take the top part with you as the bottom will hook onto your mat and keep it in place all night.

Best of all, this bag has a pillow attachment and quilt loops to secure your whole sleep system together – so you can toss and turn all you like and wake up without a crook neck. For a soundless and comfy sleep no matter what the climate the Basecamp BT4 is the one you can rely on. 

  • Four season
  • Spacious rectangular design
  • Pillow attachment system
  • Quilt loops
  • Sleeping mat sleeve
  • Versatile adjustment for all weather conditions
  • Cushioned internal hood draw-cord
  • 2-way zip on each side of the bag
  • Includes lightweight Ultra-Sil® compression bag, combined storage and laundry bag included 
Snowys Code:
Supplier Code:
Comfort Temp. Rating:
-8 °C
Lower Temp. Limit:
-15 °C
Internal Girth:
194 cm Chest | 190 cm Hip | 142 cm Foot
External Dimensions:
195L x 97W x 10H cm
Packed Dimensions:
42L x 23W x 23H cm
Compressed Volume:
14.6 L
30D Nylon Taffeta 345T with DWR
Fill Material:
THERMOLITE® insulation
20D Nylon
Zip Draft Tube:
Neck Draft Tube:
With internal drawcord
YKK #5 on each side plus separate foot zip
2.279 Kg
Suggested Use:
Camping | Hiking
Limited Lifetime

Be the first to review this product

Is this bag warmer and more long lasting than Roman -5 Palm Passport1 answer

Hi. I have a Roman Palm Passport and was happy with it until I washed it and now it is not warm enough for winter. Is this bag a warmer better quality bag than the roman and is the bulk worth it over just buying a new Roman - 5 palm passport bag? Down bags are not an option for me re ethics.

- Mayfield East(1 month ago)

G'day Jack,

The Sea to Summit Basecamp Bt4 Sleeping Bag is a much higher quality sleeping bag than the Roman Palm Passport, is rated to -8C and as long as you follow the care instructions included with the sleeping bag (Sea to Summit offer pretty comprehensive information), you should get many years of use out of the bag.

In regards to the bulk, that's probably only a question you can answer in terms of what you need it for and whether it is practical.

- Snowys(1 month ago)

What size sts compression dry sack and better than Roman Palm Passport1 answer

Hi I am interested in this sleeping bag. What size compression dry sack from Sea to Summit do you recommend?

- Mayfield East(1 month ago)

G'day Jack,

The Sea to Summit Basecamp Bt4 Sleeping Bag is a much higher quality bag than the Roman Palm Passport.

It also comes with its own compression sack and when compressed, has a volume of around 14.6 L.

- Snowys(1 month ago)

Suggested for late Spring Whistler, Canada?0 answers

Seeking a comparison between this bag and the Sea to Summit TkII Women's (please see my question posted against that product also). Which bag is suggested for late Spring in the Western Canadian mountains for a woman who feels the cold? Many thanks!

- Brisbane(9 months ago)

Can I remove the straps?1 answer

Will the pillow attachment and straps adjust enough to fit an Exped Downmat 9LW? Alternatively, can the straps be removed so they don't create lumps between the bag and the mat?

- Paynesville(10 months ago)

G'day Peter, 

I have just checked the display model that we have of the Basecamp BCII (we don't have the Bt4 on display, but it has same attachment system) and you can remove the straps and move them up and down the three mat loops positions on the bag. The straps are also very thin, so if you did leave them on, they wouldn't be much of a bother Peter. 

I have actually given this a go with the Downmat 9LW - and while it was a good 5-minute struggle, you can get it to fit onto the sleeping mat loops on the Basecamp bag. 

- Snowys(10 months ago)
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