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Marmot Reactor Review

  • Day Hiker
  • Ultralight Backpacker
  • Wilderness Backpacker

Marmot Reactor Overview

Like a fresh cup of morning coffee, the Marmot Reactor Jacket will warm your soul both at home and on the trail. In fact once you start using it, you might find you can’t live without it. The ultra-soft micro fleece is a daily comfort during the brisk months of the year and it layers well for just about any adventurous outing, whether it be on the snowy slopes, at a riverside campsite, or your neighbor’s backyard barbecue.

More than a standard fleece, the Reactor comes equipped with an elastic drawstring waist to lock in your warmth, two zippered hand-warming pockets, a zippered sleeve pocket, a wind flap, and a reinforced collar. Any fleece can keep you warm, as can any cup of coffee, but these extra features are the cream and sugar that make it just right.

We’re giving the Marmot Reactor Fleece our Classic Pick award for the Wilderness Backpacker, Day Hiker, and Ultralight Backpacker because it’s lightweight, versatile, warm, and has the right features for the price. The women’s version of the Reactor is the Flashpoint.

Check out our comprehensive guide on fleece jackets to understand where the Reactor sits in the market and why a fleece is critical to active pursuits in cold weather. Read on to see what makes the Marmot Reactor better than your average cup of joe.

Reactor Specifications

Feature Type Feature Specs What This Means
Weight 12.7 oz (360 g) Most fleece jackets weigh this much, but the Reactor is a little heavy for a lightweight fleece.
Fabric Weight Lightweight Fleeces are broken up in three weight types, and this is the lightest. This means more breathability and movement, and not as much warmth. But the Reactor is actually pretty warm. More on fleece fabric weight in our Guide.
Fabric Material Polartec Classic 100 One of the classic fleece fabrics. 100 is specific to the fabric weight, and it will feel like most of the active fleeces you know. More on fleece material in our Guide.
Fit Athletic This is a relatively tight-fitting fleece. Meant for active pursuits like hiking and backpacking.
Number of Pockets 3 Two zippered hand pockets and a zippered sleeve pocket. The hand-pockets are excellent, the sleeve is a little less useful.
Thumb Holes No No thumb-holes on this fleece, but it does have elastic around the wrists to keep some heat in.
Hood/Jacket Option No Marmot only offers this as a jacket or a vest. Bring a beanie.
Zipper Full Length The full length zipper has a wind flap behind it, greatly increasing the warmth.
Adjustable Waist Yes The waist has an elastic hem with an adjustable toggle which helps to keep in the heat.
Gender(s) Men’s, Women’s Flashpoint The men’s is called the Reactor, the women’s is called the Flashpoint. Except for fit they are the same jacket.
Sizes Available Men: S-XXL, Women: XS-XL Many options, but not an endless amount. They fit pretty true to size for an active layer.
Manufacturer Warranty Limited Lifetime Warranty Marmot offers a lifetime warranty for manufacturing defects and workmanship issues. It doesn’t cover normal wear and tear. Most useful for zippers that fail. Be sure to file a claim if something fails on this jacket.
Retail Price $95.00 Not cheap, not crazy expensive. This jacket is worth the price for warmth and versatility.

Gear Review of Marmot Reactor

Revelation: The Moment I Knew

Windy, wet, and wild makes an appropriate alliteration to describe the Oregon coast, especially so during autumn. The day hikes around here are incredible. Mossy trees, ocean views, muddy trails — it’s the best!

The Oregon coast does not want for epic views.

You have to know what you’re getting into, though, and be prepared for it. A quick jaunt through the woods often means cleaning the mud off your boots at home and throwing your clothes into the dryer.

The Marmot Reactor served me well on multiple hikes to the ocean-splitting cliffs of Yaquina Head and Cascade Head where the forest meets the sea. In drier moments the fleece worked well on its own. The breathable fleece kept me warm without making me sweat, and the added comfort of the extra features, such as the main zipper’s storm flap and chin guard, blocked the worst of the wind.

Cozy in the Marmot Reactor.

When things got wet the Reactor served as a nice buffer between me and my rain jacket. Sometimes a heavy coat was necessary, and sometimes the lighter Frogg Toggs jacket was enough, but no matter what layers I piled on I was happy to have the Reactor’s fleece close to my skin.

Digging Deeper


The micro fleece is cozy to the touch and the jacket fits snugly in all the right places. The fabric is sewn to allow a full range of arm movement without causing the rest of the jacket to ride up on you. Marmot calls this “Angel-Wing Movement” (silly, I know), but I just like to call it a well-designed jacket, especially for active pursuits.

Angel Wing Movement means you can move your arms easily. As demonstrated here.


The Reactor feels like it belongs on the warmer side of the scale when comparing it to other 100-weight fleeces I’ve worn. It uses Polartec Classic 100 Micro fleece, which many jackets use, but the reinforced collar zips high up on your neck, eliminating any need for a scarf, and the elastic hem locks in the heat down low. These extra touches make a lightweight fleece go far in terms of warmth.

The reinforced neck guard and full zipper make sure you stay warm. Most fleeces don’t pack quite this punch.


At 5’10 and 180 pounds, the medium men’s fleece fits me like a glove — a torso and arms glove, an upper body glove, a neck glove…you know what I mean. It fits well for an active layer. The hem rests a few inches below my hips, the arm cuffs reach my lower palm, the pits fit nicely in my pits, and everything else from the shoulders to the collar are on point.

It fits! Can’t you tell?

This is all for the men’s Marmot Reactor. The women’s version of this fleece is called the Flashpoint, and claims a similar tighter fit. Obviously I can’t comment on that.


The Reactor has a sharp look. Marmot’s designers added a couple of extra details that make this fleece stand out. The textured interior lining is a subtle touch, and the complimentary colors on the cuffs and collar kick this jacket up a notch in the cool department.

So stylish.


While the sleeve pocket looks nice and is functional, it’s not very large. I can fit my small iPhone 5s in the pocket, though that itself is a stretch, and most modern smartphones won’t make the cut. A small snack is the most you’ll probably ever use this pocket for. It could have been made a bit bigger, which is actually the case with almost all sleeve pockets.

I’d prefer a zippered chest pocket any day.

Final Word

For a stellar start to your day, grab a cup of your favorite coffee and wrap yourself in the cozy Marmot Reactor fleece jacket. Stave off the chilly air and look good doing it wherever your plans take you.

Where to Buy Marmot Reactor

We tested a men’s medium Marmot Reactor fleece jacket. It’s only offered as a non-hooded jacket. The women’s version of this product is the Marmot Flashpoint — it has the same features and materials as the Reactor. The only difference is fit.

Compare Marmot Reactor and Flashpoint prices below.

arthur mcmahon outdoor gear reviewer

Arthur McMahon

Arthur loves to walk. It's as simple as that. Whether it be in the mountains, on the beach, or along the city streets-- he believes walking is the best way to experience the world. Thru-hiking the Pacific Crest Trail was his first backpacking foray, and he hasn't stopped since. He and his wife chronicled their journey in their book Adventure and the Pacific Crest Trail. They now regularly travel into the wilderness of the Pacific Northwest seeking new trails to hike. Follow his adventures on Instagram. As much as he enjoys exploring the real world, Arthur also ventures into the worlds of fiction. You can learn more about Arthur's science fiction novels and his Paracosms podcast on his website.

Review Policy: We do not accept payments or gifts from brands and vendors, and strive to provide unbiased, independent advice. Brands typically provide review samples which we return, and in some cases we purchase the item so we can keep using it long after the review. Affiliate Policy: We support the hours that go into our reviews and testing through affiliate commissions on purchases made through links in this article. These don't effect the outcome of our reviews or selection of gear, as per our Review Policy.

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