Polartec for your core.

The Marmot Reactor Fleece Vest keeps your torso toasty without bulking up your arm-layers.

  • Breathable Polartec fleece boosts warm while it wicks moisture
  • Flatlock seams eliminate friction points
  • Wind flap blocks cold air from sneaking in through the zipper
  • Sleeveless design keeps your arms mobile when you're layered up
  • Reviews
  • Q & A

nice vest for skinny guys

  • Size Bought: large

I ordered a Large, but returned it. i am 5ft 11in ~44in chest and ~36in waist, ~205 lbs athletic former wrestler/football player build. I was hoping to wear this at the office over a dress shirt most often. The vest is a nice fabric but the arm holes were small for me and the fit was tight through the stomach. also seemed long for my build/height. i think if you are a slender climber this would work for you


    If you want a vest that rocks on it’s own on a chilly morning run or that keeps the bull down as you layer up for a day on the slopes, this is your vest. Did I mention it’s rather stylish as well?

    Dig this vest

    • Familiarity: I've used it several times
    • Fit: True to size
    • Size Bought: Large

    I am new to vests and am really glad I went with this one. It's a perfect layer of warm under a coat or rain shell, not bulky at all. I have worn this around town and also while mountain biking. Very comfortable, very breathable, and warm for the weight.

    Quality is really good. The fit is pretty athletic, which looks flattering, in my opinion. I'm a tall guy and the Large had plenty of length in the torso and since sleeve length isn't an issue in vests, a perfect fit.

    Terrific vest!

    • Familiarity: I've used it several times
    • Fit: True to size
    • Size Bought: Small

    The vest fits well, feels good, and I really like the look. The fit is a little bit trip, but the vest has a little bit of give to make up for small sizing differences. It's been great to have at work when it's cold and as a boost of warmth when skiing.

    Super Soft

    • Familiarity: I've used it several times
    • Fit: True to size
    • Size Bought: XL

    This vest is amazingly soft inside and out. Fits great. Runs true to size. Drawcord along the bottom if you need to cinch it up a little bit for any reason. Tow nice hand pockets and a durable chest pocket. Great casual piece or insulating layer under something else.


    • Familiarity: I gave it as a gift but have feedback to share
    • Fit: True to size
    • Size Bought: Medium

    This review is from my husband,
    This vest is awesome, I have had for a couple of years and have always loved it! It is made with really high quality materials that hold up really well and keep you warm, but not too hot at all. Great piece for layering over shirts, or layering under shells to ski or backpack in.
    I have the grey color, and really like the two toned look from the neck and pocket areas.
    I feel this vest runs true to size, I am 5'9 and around 175, and wear a Medium usually, and sized with that on this item and it fits perfectly!

    Marmot Fleece Vest

    • Familiarity: I've used it several times
    • Fit: True to size
    • Size Bought: X large

    Really like the best wear t a lot. Very true to size. Only complaint in the elastic at the bottom, which can be removed but stil. Very warm too.

    Unanswered Question

    Is the chest pocket big enough to fit a cellphone? Like iPhone or Galaxy S7?

    I LOVE this vest

    • Familiarity: I've put it through the wringer
    • Fit: True to size

    Surprisingly warm for how thin it is, makes me look fit and trim, I get compliments all the time when I wear this, I've worn it all over the US and Europe and get asked all the time where I got it. I'm shocked at how convenient I find the front and side pockets. Love this vest.

    Great cool weather option

      I took this vest with me on a recent elk hunt. Was great to wear during cool active mornings. Temps were in the 40's and it kept my core very warm.

      Very (very) Thin Polartec

      • Familiarity: I've used it once or twice and have initial impressions
      • Fit: Runs small
      • Size Bought: L

      I am returning this vest. I didn't realize how thin P100 really was.
      The cut and finish are top notch, however, I was surprised when I held it up upon "unboxing" that I could see light through the back and side panels. The pockets in the front two panels prevent light from coming through, but I have T-shirts that feel more substantial than this material. I wear a vest when the temp is in the 45-55 range, and when I tried this outside around 48 degrees I might as well have skipped the vest - no noticeable warmth, and any light breeze goes right through. (I find it odd that the description touts a wind blocking zipper flap when wind goes right though everywhere else) Maybe fine beneath a wind breaker, but it doesn't work for me.
      Normally I wear XL for jackets only due to sleeve length, so I ordered a large (43" chest, 35 waist) and found it a too tight across the shoulders and through the arm holes. Length was good, and I'm long in the torso.

      Great Fitting

      • Familiarity: I've used it several times
      • Fit: True to size
      • Size Bought: Large

      I received this as a gift a year ago and while I normally prefer jackets, I've loved wearing this vest. I enjoy wearing it with a flannel shirt for cool fall/spring days. I'm 6'5" with a 32" waist and size large fits me perfectly.


      • Familiarity: I gave it as a gift but have feedback to share
      • Fit: True to size

      I got this for my girlfriend's dad, who's a home inspector, so he crawls around in attics and basements all day. I thought this would help keep him warm without being as restrictive as a coat. He likes it for that reason and also because it has a small chest pocket where he can keep a pen and flashlight handy.

      Need a Vest

        I got this for my Dad,

        I enjoys the length and how it fits, He likes the fact it has a side chest pocket so its easy for him to put the wallet and the side pockets for keys and ect. Its light and easy to pack and drutable and he loves wearing it skiing.

        It was a great fit, and looks sharp.