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Extend the life of your sleeping bag and trap a little extra warmth with the Sea To Summit Thermolite Reactor Plus Compact-Length Mummy Liner. Built with insulating Thermolite fabric, this liner traps heat without over-bulking your pack. Furthermore, it keeps the inside of your bag clean and gives it a break from the wear and tear of normal use.

  • Drawcord hood for facial protection
  • Comes with lightweight Ultra-Sil stuff sack

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Sea To Summit Thermolite Reactor Plus Compact-Length Mummy Liner

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Here's what others have to say...

Will this liner work for both left and right zip mummy style sleeping bags?

Best Answer

Yes. They are open at the top so it does not matter what side your bag zips. These liners are a great addition to any sleeping bag. Keeps them clean and adds a little extra warmth. Best part is that you can have your bag unzipped to breath when in warmer temps with out getting darn right cold. Hope that helps!

4 5

Compact and warm - worth it

  • Familiarity: I've put it through the wringer

Owned this for over a year now, and I have to say I'm happy with it. It won't blow you away--there is only so much warmth you can expect from something only a little bigger than a soda can, but it makes a nice difference. I couple this with a 40 degree bag and it makes a warmer, more compact sleeping arrangement than a 20 degree bag, I think. It also keeps the bag clean, which is nice when I am cold and want to wear my dirty clothes in the bag. The only thing, I'm 5'11" and I would have gotten a slightly longer version if I could, it's just barely tight with when I try to shut the mummy and lie flat.

All in all, I think it's fairly advertised, it's comfortable and keeps me warm enough that I always bring if it even might get cold.

Can this be machine washed?

Can this be machine washed?

Best Answer

Sea to Summit Care Instructions:

Care of Sea to Summit liners is very simple: unlike some synthetic waterproof / soft shell fabrics which have to be washed in special non-detergent soaps, the liners can be washed in a home washing machine using normal detergent (referred to as laundry ?soap?). If you are using a top-loader washing machine, we would strongly suggest putting the liner inside a pillow case to prevent the impeller (the spiral plastic rotating column in the drum of the machine) possibly snagging the draw cord. A front-loader is much gentler on your gear, and this step is unnecessary. In either case, use the delicates or gentle cycle. Fabric softener will decrease the wicking performance of the fabric, and should be avoided. Do not dry the liner in a dryer; excessive heat can damage the fabric ? air-drying is the way to go.

Always use plant based soaps and fabric will last longer and stay stronger. I think that also applies to things like skin and produce..

1 5

Not impressed

  • Familiarity: I've used it once or twice and have initial impressions

I do alot of winter and shoulder season hiking. I had a recent issue with my 0 degree synthetic bag where I chilled over night and was very uncomfortable, so on the next trip I picked up a reactor plus and tried it out. needless to say I can't see how they can tout this liner to add 20 degrees to the bag rating. Was I slightly warmer? it's hard to say, meaning I didn't notice a difference and I was still cold over night. Almost seems like a gimmick to me. I'm keeping it for a warm weather lite liner.

Dude, your body has to produce heat for a liner or even an 850-fill sleeping bag to retain heat. Don't do the things that cause your body to generate heat before you get into a bag, you'll be cold in very cold weather. That is a user error, not the fault of the bag.

I too do regular winter camping, on snow & on dry or wet ground, down to -10F. I appreciate the Reactor's fleece when I first get into my non-fleece lined 0F bag, and I do find that I stay a bit warmer using the reactor. Perhaps best yet, my body's oils & dirt transfer to the reactor, which is easily washable while my beloved 0F 800-fill bag stays clean.

What to do to generate heat BEFORE getting in your bag? Think: drink some hot (non-alcoholic) liquid. Eat, esp. fats. Go for a brisk walk that gets your metabolism going. Soak in a hot spring. Put a Nalgene bottle filled with very warm water into your bat. And of course there is sex, but that is problematic at 0F...!

5 5

Perfect to extend your bags season

I don't have a need for a winter sleeping bag but I do like to camp in the shoulder seasons when temps can drop down to the 30's. I picked up the reactor liner for myself and the reactor plus for my wife. If you really want the extra warmth i'd grab the reactor plus. Its noticeably thicker and does add substantial warmth (Sea to Summit suggests it adds 20 degress while the reactor adds 15). Again, extra comfort, keeps your bag clean, and adds warmth for 9oz. I was on the fence on if this was worth $60 but it is totally worth it. You can also use it as your bag in the summer or take it on travels when you don't trust the bed sheets.