Front view of Hyperlite Mountain Gear's Prism 40 Pack in White
Hyperlite Mountain Gear Packs Prism 40
Left side view of Hyperlite Mountain Gear's Prism 40 Pack in White
Right side view of Hyperlite Mountain Gear's Prism 40 Pack in White
Back view of Hyperlite Mountain Gear's Prism 40 Pack in White
Hyperlite Mountain Gear's hip belt with gear loops and ice clipper slots removed from Prism 40 Pack
Detail shot of Hyperlite Mountain Gear's Prism 40 Pack in White
Detail shot of the exterior strap on Hyperlite Mountain Gear's Prism 40 in White
Detail shot of the external diamond pocket on Hyperlite Mountain Gear's Prism 40 Pack in White
Close up shot of the reflective bungees with quick-release pull tabs on Hyperlite Mountain Gear's Prism 40 Pack in White
Detail shot of the exterior seams on Hyperlite Mountain Gear's Prism 40 Pack in White
Side sleeve pocket and buckle on Hyperlite Mountain Gear's Prism 40 Pack in White
Detail shot of the drawstring closure system with extendable collar and cinch cord on Hyperlite Mountain Gear's Prism 40 Pack in White

Prism 40

4.5
Rated 4.5 out of 5 stars
75 Reviews
Torso Length
Weight: 34.2 oz
Availability: In stock, ready to ship
$425.00

How to Choose a Pack Size

Your torso length, not your height, determines your pack size. We recommend the following to determine yours:

  1. Tilt your head slightly forward to locate the bony bump at the base of your neck. (This is your 7th cervical (or C7) vertebra).
  2. Using a flexible tape measure, have someone measure starting at that spot and running down along the curve of your spine.
  3. Place your hands on your hips so you can feel your iliac crest, which serves as the “shelf” of your pelvic girdle. (It’s the first hard thing you feel when you run your fingers down from the sides of your ribcage.) Position your hands so your thumbs are reaching behind you.
  4. Have your friend finish measuring at the point where the tape crosses an imaginary line drawn between your thumbs. This distance is your torso length.
    • Small (15.0” - 17.0” torso)
    • Medium (17.0” - 19.0” torso)
    • Large (19.0” - 21.0” torso)
    • Tall (21.0”+ torso)
  5. If your measurement falls right in between sizes (for example, if you have a 17.0” torso, so you are right on the line between a Small and a Medium), we suggest you choose the larger torso size.

WATCH THE VIDEO


How to Choose a Pack Size

How to Choose a Pack Size

Your torso length, not your height, determines your pack size. We recommend the following to determine yours:

  1. Tilt your head slightly forward to locate the bony bump at the base of your neck. (This is your 7th cervical (or C7) vertebra).
  2. Using a flexible tape measure, have someone measure starting at that spot and running down along the curve of your spine.
  3. Place your hands on your hips so you can feel your iliac crest, which serves as the “shelf” of your pelvic girdle. (It’s the first hard thing you feel when you run your fingers down from the sides of your ribcage.) Position your hands so your thumbs are reaching behind you.
  4. Have your friend finish measuring at the point where the tape crosses an imaginary line drawn between your thumbs. This distance is your torso length.
    • Small (15.0” - 17.0” torso)
    • Medium (17.0” - 19.0” torso)
    • Large (19.0” - 21.0” torso)
    • Tall (21.0”+ torso)
  5. If your measurement falls right in between sizes (for example, if you have a 17.0” torso, so you are right on the line between a Small and a Medium), we suggest you choose the larger torso size.

WATCH THE VIDEO


How to Choose a Pack Size

The Prism 40 is the ultimate pack for technical alpine ascents and ice climbing, perfectly blending weight, security, and comfort. Built with exclusive 400D Fully Woven Dyneema, it’s designed to withstand the rigorous demands of ice climbing and mountaineering.

DESIGNED FOR:

Ice Climbing, Alpine Ascents

KEY FEATURES:
  • Drawstring closure with extension collar and lid provides quick access to your gear while ensuring a secure, weather-resistant seal.
  • Diamond tool pocket securely carries technical ice tools, keeping them organized and easily accessible during climbs.
  • Crampon pouch offers easy and safe storage for your crampons, preventing damage to the pack and allowing quick access.

WHY CHOOSE THE PRISM 40?

A white triangle logo on a black background.

REMOVABLE FLOATING LID

Sized to accomodate items you need quick access to throughout the day

A white triangle logo on a black background.

DRAWSTRING CLOSURE & WATERPROOF MATERIALS

Easy to open and close with gloves on for loading or unloading gear. Pair with our Stuff Sacks for a buttoned up, nearly waterproof kit

A white triangle logo on a black background.

HIGHLY ADJUSTABLE

Compression straps secure crucial equipment while keeping the pack close to the body for free and unrestricted movement
4.5
Rated 4.5 out of 5 stars
Based on 75 reviews
Total 5 star reviews: 50 Total 4 star reviews: 16 Total 3 star reviews: 6 Total 2 star reviews: 2 Total 1 star reviews: 1
89%would recommend this product
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75 reviews
  • Sarah H.
    Verified Reviewer
    Age Range 25 - 34
    What activities did you use this product for? Alpine/Ice Climbing
    What size pack did you order? Small
    9 months ago
    Age Range 25 - 34
    What activities did you use this product for? Alpine/Ice Climbing
    What size pack did you order? Small
    Rated 5 out of 5 stars
    Best alpine ice pack

    Have put this pack through ringer for 3 years now and it has held up. Most comfortable pack I've owned whether it's weighed down for the approach or cinched down for the climb.

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  • Veraun C.
    Verified Buyer
    Age Range 25 - 34
    What activities did you use this product for? Backpacking, Thru Hiking, Day Hiking, Alpine/Ice Climbing
    What size pack did you order? Small
    1 year ago
    Age Range 25 - 34
    What activities did you use this product for? Backpacking, Thru Hiking, Day Hiking, Alpine/Ice Climbing
    What size pack did you order? Small
    Rated 5 out of 5 stars
    Prism 40

    The best pack hands down for ice and alpine climbing! Been using my own for a couple of years now, and bought one for Christmas for my daughter.

    This is HMG pack #6 for my family!

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  • Joshua S.
    Verified Buyer
    Age Range 25 - 34
    What activities did you use this product for? Alpine/Ice Climbing
    What size pack did you order? Medium
    1 year ago
    Age Range 25 - 34
    What activities did you use this product for? Alpine/Ice Climbing
    What size pack did you order? Medium
    Rated 5 out of 5 stars
    Best light weight simplistic minimalist pack out there

    Great pack, really ticks all the boxes. Light weight, simplistic, minimalistic, super durable, VERY comfortable. great features. I measured my torso and went with a Medium. Should have got a size small unfortunately. But I will just have to get by

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    HM Profile picture for Hyperlite Mountain Gear
    Hyperlite Mountain Gear
    1 year ago

    Hey Josh, thanks for the review! Reach out to the Customer Service team to get the fit of your pack assessed. They should be able to help you out with this!

  • Wayne P.
    Verified Buyer
    Age Range 35 - 44
    What activities did you use this product for? Alpine/Ice Climbing, Skiing/Snowboarding, Day Hiking, Thru Hiking, Backpacking
    What size pack did you order? Medium
    2 years ago
    Age Range 35 - 44
    What activities did you use this product for? Alpine/Ice Climbing, Skiing/Snowboarding, Day Hiking, Thru Hiking, Backpacking
    What size pack did you order? Medium
    Rated 5 out of 5 stars
    Changing the game

    Amazing and great pack! Light and extremely durable!

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  • Daniel T.
    Verified Buyer
    Age Range 35 - 44
    What activities did you use this product for? Backpacking, Alpine/Ice Climbing, Day Hiking
    What size pack did you order? Medium
    2 years ago
    Age Range 35 - 44
    What activities did you use this product for? Backpacking, Alpine/Ice Climbing, Day Hiking
    What size pack did you order? Medium
    Rated 5 out of 5 stars
    Great mountaineering pack

    Comfortable, durable, lightweight… just love it.

    Brain (top cover), would be great to be able to adjust hight (velcro side), depending on the amount of load inside.

    But overall great backpack.

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