Sea To Summit Reactor Thermolite Sleeping Bag Liner

I love this bag liner. Take it on every trip with me just in case it gets cold. I used this one night in15 degrees and my bag was a 40. I was never cold. In fact it was one of the best sleeping camp nights I've ever had.

Only gave it a four because I wish you could UAE it alone in cold weather. I've triedto use it in 60 by itself and got pretty chilly.

Bottom Line: if your looking for a great bag liner, look no further, you will never beat this one for weight, compactness, and warmth. It's the trifecta.

I don't see how this really adds 15 degrees of warmth, though I still use it as part of my down system. Like any other liner, it helps keep the sleeping bag clean, packs small, and weighs little. Soft material feels great. It is honestly so thin that you can see through it, though I took it to the smokey's in TN this summer and used it alone as my sleeping bag.

Essentially this is a giant polyester sock. It feels quite thin (you can
see through it if you hold it up to light). I don't know about 15
degrees, but it did add a noticeable amount of warmth to my 30 degree
bag on a cold night. The drawstring comes out on the left by default but
with a little effort I moved it to the right. I didn't feel like it
inhibited motion in my sleeping bag, and it was relatively easy to get
in and out of.
It may be a little heavy (and expensive) for what it does. After all, it
won't be as efficient as down for its weight. If you bring it and don't
need it, at least it makes a decent pillow.

This fabric liner is effective -- though doesn't really add 15 degrees of comfort to a 3 season bag. The stuff sack doesn't compress, and is just big enough for the sack. In my experience, it is way too much work to get it back inside; I just add it to the compression sack that I use for the sleeping bag. It does look like it would work nicely as a stand-alone bag in the hot weather.

nice to use alone in warm weather..also packs up small and is very light

I bought this liner after reading some reviews about it and became instantly skeptical when I saw how thin the liner is (as someone said, you can see through it) but I was impressed by the liner. It doesn't give the 15 degrees it says (10 is more accurate) but it can't be beat for comfort or packability

I've used this liner for awhile now, and it is definitely nice to have on the cold nights. I agree that it doesn't quite add 15, more like 10 degrees to your bag. It also feels nice next to your skin and adds quite a bit of comfort to your bag.