G'day Mark,

No, you're not able to zip 2 x Trek sleeping bags together.
With Sea to Summit, for each unisex bag there is a women's specific equivalent, and these two bags can zip together.
In the case of the Trek, the women's specific partner bag is the Journey series - you'll be able to zip any of these two combinations together.

G'day David,

There isn't any specifications around upper temps for sleeping bags, but when fully opened out, you could use this bag in most climates. I have a similarly rated bag that I've used in the middle of summer, with overnight temps around 15-20C and haven't found it too hot.

G'day Sam,

THe Trek sleeping bags are supplied with an Ultra Sil Compression Sack that is water-resistant, but if you're needing something waterproof you'd need to grab yourself a Compression Dry Sack in Medium.

G'day Toby,

It's not recommended to wash Down at a high temperature. For more tips have a read of our blog HERE

G'day Jay,

Thanks for getting in touch, both the Trek TKIII and Spark SP3 use ULTRA-DRY Down™ which helps to reduce moisture affecting the down. Generally, condensation will form on the outer surface if you're too warm in the bag and there is low breathability in your tent. We'd suggest ensuring your tent has good breathability, and opening up roof vents etc to help reduce condensation. Both bags will perform in the same manner, so we'd suggest choosing a bag based on the comfort temperature you require. 

G'day Justin,

The Trek TK3 has a comfort temperature of -6'C, you can read more about how sleeping bag temperature ratings work in this handy blog post. As long as you're sleeping on a well-insulated mat, in a tent, you should be comfortable, down to -6.

G'day Tory,

You can use Trek Tk3 inside a bivy without too many worries. The Trek TK3 has a breather 30D nylon outer shell so condensation will usually form on the inside of the bivy. If the bag itself gets wet then it shouldn't cause too many issues as Sea to Summit uses ULTRA-DRY Down™  which is a water-repellant treatment that protects the down from external moisture and condensation. 

G'day Bruce,

My apologies.  As they are the new 2019 model we have them on backorder with Sea to Summit. We have a limited number due to arrive late April, however there is a pre-order option available above.  If you choose to place the pre-order it will get shipped out to you as soon as they land.

G'day Bruce.

The Long model in the Trek series has a max user height of 198cm / 6'6".  One of the guys here has jumped into the regular size, which he exceeds measurements by about an inch, and it was quite uncomfortable.  You can see him trying it at aroun 4:35 on our Trek TK Down Sleeping Bag Range video.

It might be possible that you would get away with the Long model although not using the hood.  I would recommend you find somewhere to try it out in person before you make a decision, as there are other factors with the fit aswell, especially when around the max user specs.