Hyperlite mountain gear Prism Pack 40

Hyperlite Mountain Gear Prism 40

The Prism 40 is a technical alpine backpack developed for ice climbing and demanding alpine ascents. It combines low weight, high durability and stable carrying comfort in a design adapted for steep and technical environments. The backpack is built in 400D Fully Woven Dyneema® that can withstand hard wear from ice, rock and equipment - while keeping the weight low.

With smart solutions for ice tools, crampons and other climbing gear, the Prism 40 is made for climbers who need a reliable pack on serious alpine tours. The expandable design and floating top cap allow the pack to easily adapt to the length of the trip and equipment needs.

Features include

Durable Dyneema® Woven Composite and Dyneema® Composite Hybrid construction

Volume: 40 L + 15 L with extension collar and top lid

Diamond tool pocket keeps ice axes securely in place without extra buckles

Separate crampon pocket for safe and easy access storage

Reflective bungee attachments with quick release axe handle

Removable hip belt with gear loops and ice clipper attachments

Removable aluminum stay for stable carrying structure

Four side compression straps for stable packing or attachment of equipment

Daisy chains on shoulder straps and front for extra gear

Weather-resistant construction with taped seams in exposed areas

Specifications of the bag

Volume: 40 L + 15 L

Weight: 981 g

Maximum load: up to 22.7 kg

Material: Dyneema® Composite Hybrid + Dyneema® Woven Composite 5.0

Back width: 27.9 cm

Height: 55.9-77.5 cm (88.9 cm fully unrolled)

Made in: Mexico



How to choose the right back size

It's your torso length - not your height - that determines which size backpack you should choose. Here's how to measure it:

Tilt your head slightly forward and feel for the bump at the base of your neck. This is your seventh cervical vertebra (C7) and the starting point for the measurement.

Measure along the spine
Ask someone to help you measure with a soft tape measure from the C7 vertebra down the natural curve of your spine.

Find the iliac crest

Put your hands on your hips and feel for the top of the hip bone - roughly where a hip belt would rest. Place your hands so that your thumbs point backwards.

Finish the measurement
The measurement ends where the tape measure crosses an imaginary line between your thumbs. That distance is your back length.

Sizes
Small: 38-43 cm (15-17")
Medium: 43-48 cm (17-19")
Large: 48-53 cm (19-21")

Tip: If your measurement is exactly between two sizes, it is usually recommended to choose the larger size for the best fit.