Merino Wool Boot Socks - Heavy Expedition | FITS®

Heavy Expedition - Boot

219 reviews

Heavy Expedition - Boot

219 reviews

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  • The ultimate combination: Merino wool for cold weather insulation and the performance that comes from a perfect fit. There is no other heavyweight sock that can make this claim. If there were, we would have made it! This sock is loaded with 100% Merino wool on the inside against your foot, so all you feel is comfortable and dry.

    • Heavyweight full-foot cushioning for warmth and protection.
    • Durable nylon exterior for extended wear.
    • Mid-calf height works well with hunting boots.
      Merino Wool 82%
      Nylon 13%
      Polyester 3%
      Lycra® Spandex 2%

    Customer Reviews

    Based on 5 reviews Write a review

    Designed to be the best socks you've ever worn.


    Moisture Wicking

    Designed for stay-dry breathability & performance


    Full Contact Fit

    No uncomfortable bunching, slipping, or rubbing


    Smart Cushioning

    Extra padding in active zones: toe, arch, & heel


    2-Year Warranty

    Quality-made in the USA & guaranteed to last

    Merino Wool

    All our socks are made with 18.5m superfine knit, suit-grade performance Merino wool.

    Odor Resistant



    Omega Performance Yarn

    Our custom blend of man-made fibers selected for the best breathability and fit.



    Moisture Wicking

    Customer Reviews
    5.0 Based on 219 Reviews
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    Blue K.
    United States United States

    The Best amand I have tried them ALL

    Fits socks are really, really well made and very well thought out. These socks are being tested by the US military as we need to field more troops to cold weather locations, we need better gear. I know a lot about wool as my wife is a knitter, the complexity of design and the zone warmth in the heel and toe make this sock a dream.

    Mary K.
    United States United States

    Couldn’t be better

    We give an excellent on Fits Socks. We especially like the close almost massage like feel when we put them on.

    Erek S.
    United States United States

    Fits Heavy Expedition Boot Sock

    These socks are absolutely terrific. I live in Maine. I have worm them for 4 winters now. I begin wearing them in late November. I don’t stop wearing them until mid-April. Comfortable and always warm, warm, warm. Best I have ever owned. And I have tried them all. I am a total convert. Also, they hold up excellently after repeated washing.

    Simon L.
    Canada Canada

    Heavy Expedition - Boot

    In all honesty those socks are amazing. Thx FITS

    Tasha B.
    United States United States

    My favorite socks!

    My favorite socks are the FITS brand hands down. The Heavy Expedition socks are perfect for my active outdoor life, my feet stay toasty even when the temps are not!

    Ricky S.
    United States United States

    Heavy Expedition

    This isn’t the first pair of these socks I have ordered. I appreciate the warmth, comfort, and longevity of wear these socks provide in my work boot, in the cold season. Additionally, like with all my FITS socks they stay up on my leg and in place on my foot.

    Travis H.
    United States United States

    Heavy expedition sock

    I wear these socks over 40 hours per week. On my feet all day and walk constantly. They have keep me comfortable and held up very well

    Carmen P.
    United States United States

    Best socks !

    I work up in North Dakota. I have had a hard time finding a sock that can withstand the cold and keep my feet dry. I work outside a lot so that was very important. These really have made a difference. Obviously when it’s down to certain temps nothing can keep you warm. But these have been the best so far. Highly recommend for those who want comfort.


    Sock Sizing
    women and men size chart

    The Perfect Fit Starts With the Right Size.

    Your sock size shouldn’t be a guessing game. Our socks range from small to double XL, but the best way to know the perfect fit for you is to match your shoe size to the chart on the left. That way, you’ll know the size you select will give you the fit and feel you expect.

    Between sizes? Go with your gut, but rest assured that your socks will still fit great. If you receive your order and find yourself wishing you’d gone up or down a size, just let us know. We’ll happily send you replacements for your preferred size.

    Concerned about laundry mix-ups? All FITS® socks are coordinated by color and size, based on the colors you see on the size chart. So, you won’t have to worry about mixing up your sizes with the other FITS® wearers in your home. (But stray socks mysteriously going missing in the dryer? Unfortunately, we can’t help with that.)


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    How Do You Determine Sock Size?

    Sock sizes are typically measured in inches, not by your shoe size. So, a sock size 6-8 will comfortably fit someone whose feet are between six and eight inches long. However, at FITS®, we make it easy for you to choose the ideal sock size without having to measure your foot. Simply use our sock size conversion chart based on your shoe size to select the right fit for you. 

    How Do You Measure Your Foot for Socks?

    To measure your foot for socks, measure the length from the heel of your foot to the tip of your longest toe. The measurement in inches correlates to your sock size. For example, if your foot is 10 inches long, a sock size 9-11 should fit you comfortably. At FITS®, you can skip this step and find your sock size based on your shoe size using our conversion chart. 

    What Is the Sock Size Conversion?

    The sock size conversion refers to sock size compared to shoe size. While all companies may vary slightly on which size socks to purchase based on your shoe size, you can always measure your foot to find the right fit for you. 

    What is Sock Size to Shoe Size?

    Because sock sizes are determined by the length of your foot in inches vs. your shoe size, shoe and sock sizes differ. The FITS® sock size to shoe size conversion is as follows:

    Knowing this makes it easy to choose the ideal sock size based on your shoe size without measuring your foot. 

    What Age is Sock Size 9-12?

    Sock sizes typically don’t correlate with age. For kids, age can be a general indicator of what size sock they’ll need, but everyone is different. An adult sock size 9-12 fits anyone whose feet are approximately nine to twelve inches long. For kids’ sock sizing, check with the company to find exact details to ensure your little one gets the perfect fit. 

    Got more questions about finding the perfect sock size for you? Let’s talk.



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