A very poor conductor of heat, silk will trap a lot of warmth within the liner making it a very warm liner in a very compact unit.

A silk liner is also a must have when travelling in hotter climates - if you use it on its own it will help you feel cooler when it gets too hot to sleep in your sleeping bag.

It adds approximately 5 degrees to the temperature rating, but is much smaller than the TS-1 liner. Snugpak