Front view of Hyperlite Mountain Gear's Prism 40 Pack in White
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

Rated 4.5 out of 5
Based on 73 reviews

Designed for technical alpine ascents, this 40L pack with drawstring closure and floating lid strikes the balance of speed, weight, security, and comfort.

Torso Length
Weight: 36.3 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

With external diamond pocket to lock two technical axes in place, an external crampon pocket, and a drawstring closure with floating lid, this pack is ideal for ice climbing, mixed climbing, and mountaineering. Primary features include:

  • Ice axe loop for a traditional mountaineering axe
  • Top-loading pack with lid featuring a zipper pocket
  • Over the top strap helps compress and secure a rope
  • Removable hip belt with gear loops and ice clipper slots
  • Low-profile side pockets for securing pickets/wands

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
average rating 4.5 out of 5
Based on 73 reviews
  • 5 Stars
    50 Reviews
  • 4 Stars
    14 Reviews
  • 3 Stars
    6 Reviews
  • 2 Stars
    2 Reviews
  • 1 Star
    1 Review
89% of reviewers would recommend this product to a friend
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Rated 0 on a scale of minus 2 to 2, where minus 2 is Too Small, 0 is Just Right and 2 is Too Big
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Rated 4 out of 5
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Review posted
Reviewed by 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
Rated 5 out of 5

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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How was your pack fit?
Rated 0 on a scale of minus 2 to 2, where minus 2 is Too Small, 0 is Just Right and 2 is Too Big
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Rated 4 out of 5
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Review posted
Reviewed by 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
Rated 5 out of 5

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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Rated 5 out of 5
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Review posted
Reviewed by Steven D.
Verified Buyer
Age Range
65+
What activities did you use this product for?
  • Alpine/Ice Climbing
What size pack did you order?
Tall
Rated 4 out of 5

Almost perfect ice climbing pack

I liked everything about this pack (compared to other “ice climbing pack designs”. Only wish it had a larger top pocket to accommodate extra mitts, first aid kit, beacon.

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How was your pack fit?
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Rated 5 out of 5
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Review posted
Reviewed by 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
Rated 5 out of 5

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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How was your pack fit?
Rated 2 on a scale of minus 2 to 2, where minus 2 is Too Small, 0 is Just Right and 2 is Too Big
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Rated 3 out of 5
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Hyperlite Mountain Gear

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!

Review posted
Reviewed by 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
Rated 5 out of 5

Changing the game

Amazing and great pack! Light and extremely durable!

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How was your pack fit?
Rated 0 on a scale of minus 2 to 2, where minus 2 is Too Small, 0 is Just Right and 2 is Too Big
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Rated 4 out of 5
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