• Insulated Forty Below K2 Superlight Boot Cover Black and red with a visible white brand logo on a white background
  • Insulated Forty Below K2 Superlight Boot Cover Black with a visible white brand logo on a white background side profile
  • Insulated Forty Below K2 Superlight Boot Cover Black and red other side view showing black protective patch on side
  • Insulated Forty Below K2 Superlight Boot Cover Black and red front toebox closeup showing protective durable coating
  • Insulated Forty Below K2 Superlight Boot Cover Black and red bottom sole pattern black and grippy
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Forty Below

Forty Below® K2 Superlight Overboot

Forty Below® K2 Superlight Overboot

$259.95 USD
$259.95 USD
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Shipping calculated at checkout.

⚠️ PLEASE NOTE: Extremely limited sizes available.

Sizes available (boot sole length): (XS 10-10.9 in) (S: 11-11.75 in) (XL 13.25-13.75 in) (XXL 13.75-14.25 in)

If your boot does not fit these sole lengths, please contact us for information on when these sizes will be available in the near future.

Please provide your boot details in the fill-in sections below. We will pick the correct size for you.
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The Forty Below® K2 Superlight™ model has been used for decades on Denali, the Himalayas, Polar expeditions, and cold wilderness travels around the world.  Fits double shelled and single boots for mountaineering and expedition use. 

"I wouldn't go to extreme altitude without them" JIM WICKWIRE, the first American to summit K2

The Forty Below® K2 Superlight™ is made with a special nylon-covered, 5 mm stretchy closed-cell neoprene foam insulation. This insulation wraps from the top of your climbing boot completely around and under it, leaving no gaps. The insulation panels are glued and stitched on both the inside and outside surfaces, with no sewn-through seams. They fit snugly to the boot without being bulky. Thanks to the stretchiness of the material, they’re easy to put on even in the cold, and they roll up compactly to fit in your pack.

The toe and heel areas feature small, triangular-shaped panels made from slightly thinner neoprene insulation. This design allows many wire toe bails and flip-lever heels to simply compress the insulation and rest securely in the toe and heel grooves of the boot. The toe, heel, and lower side areas of the overboots are coated with a thin layer of rubberized paint to increase abrasion resistance and help protect the stitching.

The front closure is a heavy-duty 2 inch wide Velcro front closure and runs all the way down to the toes, allowing easy access for lace adjustment. The upper gaiter extends to just below the knee and is made from non-coated, windproof, and breathable Cordura® nylon to help reduce frost build-up. An elastic drawcord closure with a cord lock secures the top of the gaiter. Additionally, a smooth nylon crampon patch is glued and stitched to the instep side of the neoprene for extra resistance against crampon punctures.

One great feature of Forty Below® overboots is how easy they are to repair. Crampons and rough terrain can be tough on gear, but small poke holes can be quickly fixed using neoprene glues like AquaSeal (for waders or wetsuits). For the fabric gaiter, iron-on patches work well and often eliminate the need for sewing. For on-mountain fixes, use the included Forty Below® Repair Patch—a sticky, stretchy tape designed for quick field repairs.

Included is one of our “peel and stick” stretchy Repair Patches for use when on a trip.

  • Features & Details

    • Knee-height design with non insulated upper gaiter and fully insulated lower coverage around and under the boot
    • Made with 5mm stretchy neoprene closed-cell foam covered in durable nylon
    • No gaps in insulation – panels are glued and stitched (inside and out) with no sewn-through seams
    • Trim fit — not bulky
    • Compatible with a wide range of crampon binding styles
    • Toe and heel feature triangular thinner neoprene panels for crampon toe bails and heel levers to compress and rest securely
    • Reinforced with thin rubber paint on toe, heel, and lower side areas for abrasion resistance and extra durability without losing stretch
    • 2 inch heavy-duty velcro front closure for easy access to boot lacing.
    • Easy to repair – crampon poke holes can be glued
    • Repair instructions included and available HERE

  • Ordering Info

    • Use the fill-in boxes above to provide your boot brand, model, size, and sole length. (We will select the best fitting size)
    • Sizes: XS–XXXL (fits from women’s 4 to men’s 18. Fits over single and double-shelled mountaineering boots)
    • Colors: Black/Black, Red/Black
    • Weight: Only 20 oz / 560g per pair (size Medium)
    • Hand-built in Canada!

Crampon Compatibility

  • Forty Below K2 Overboot red side profile showing crampon attached strap toe flip lever heel style

    Strap Toe/Flip Lever Heel

    Double Boots & Single Boots

  • Forty Below K2 Overboot red side profile showing crampon attached wire toe flip lever heel design

    Step in Wire Toe/Flip Lever Heel

    Double Boots Only

  • Forty Below K2 Overboot red side profile showing crampon attached strap on binding style

    Quick Strap-On Binding

    Single Boots & Double Boots

Please Note: Single boots typically do not work with overboots and “wire toe bail” crampon bindings, as there is usually not enough space on the toe groove to accommodate both the crampon bail and the overboot fabric. Feel free to contact us with any questions or to discuss your specific setup.

WARNING:
The user must try on the crampons to each boot and overboot combination to confirm a proper fit! Some crampons will not fit certain combinations due to the condition of the boot, crampon, or shape and size relative to the shape and size capabilities of the crampon. The user must confirm proper fit prior to using. Please contact us if you have any questions or would like to discuss this for your specific set-up.

PLEASE NOTE: CAUTION
Using overboots with some snowshoe bindings advisory:
These overboots are strong, but will not resist the damage that can be caused by some snowshoe binding base plates. There are now several models of snowshoes with upward facing “spikes” and “raised ridges” made of strong plastics and sharp shapes, that will immediately cut into the fabric sole of the overboots, and is very difficult or impossible to repair. The general purpose of these snowshoe binding design is to grip the rubber sole of the boot that is in the binding. Many of these spikes and sharp shapes have shown to cut into the rubber of the sole of boots. It is advised to put a thick rubber layer on top of the snowshoe binding base to protect the overboot from damage. This type of damage to the overboots will not be covered under warranty. We do have some suggestions on different ways people have made accommodations to this, so please contact us to discuss.

See it in Action (Double Shelled Mountaineering Boots)

(Click or tap image to enlarge and view description)

See it in Action (Single Mountaineering Boots)

(Click or tap image to enlarge and view description)

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