UltrAspire Hydration Pack - Altruist
Overview
The Altruist Hydration Pack is part of our Pure Mountain Running line, designed for athletes who move with purpose through environments that constantly test both gear and resolve. Built for long efforts where reliability matters most, the primary body utilizes challenge cloth — a three-layer composite combining high-density polyester, UHMWPE fiber reinforcement, and a protective polyurethane film. The result is a fabric that delivers exceptional abrasion resistance while remaining remarkably lightweight, ready to withstand sharp rock, dense brush, and the relentless friction of miles in the mountains.
Supporting this foundation is our EnduraMesh XT, a true 4-way stretch mesh engineered to move naturally with the body. Where conventional stretch materials fatigue and fail, EnduraMesh XT integrates Nylon 66 for structural strength with 30% UHMWPE fibers, a material rated up to 15 times stronger than steel. This creates adaptive storage that maintains its integrity over time, ensuring secure carry and consistent performance through demanding conditions.
Every fabric choice in the Altruist reflects a commitment to durability, movement, and trust — because when the terrain pushes back, your gear should remain the one constant you can rely on.
Recommended Use:
The Altruist is designed for multisport athletes and endurance adventurers who need a versatile, high-capacity pack built to handle everything. Ideal for ultrarunning, adventure racing, mountaineering, and long backcountry adventures where carrying a variety of gear is essential. Perfect for athletes who demand fast access, durable construction, and all-day comfort across unpredictable terrain and changing conditions.
Weight: 2 lb 1 oz w/frame (935g), 1 lb 14 oz w/o frame (850g) Features Key Features
- 28-litre roll-top design built for multisport and endurance athletes
- Durable construction with premium materials for rugged, all-condition use
- Massive side pockets fit all UltrAspire hydration options and allow fast gear access
- Externally accessible, insulated reservoir sleeve for efficient mid-effort refills
- Large quick-stash outer pocket with compression for secure load management
- Anodized aluminum buckles provide reliable attachment for poles, ice axes, or hose management
- MaxO2 sternum system with adjustable toggle buckle for custom fit and breathability
- Front harness includes a zippered bottle pocket with weather protection
- Layered zippered pocket at the fingertips for quick-access items
- Sweat-proof lined phone pocket keeps electronics protected
- Dual zippered top shoulder pockets for additional organization Technical Specs
- Fit: SM/MD: Waist 27″-38″ Torso 15.5″-18.5″, MD/LG: Waist 29″-42″ Torso 17.5″-20.5″
- Sizes: SM/MD, MD/LG
- Color: White/Black
- Hydration Included: Not Included
- Bottle Compatible: UltraFlask 550 Hybrid Bottle, Softflask 300/500/625/800/1L
- Capacity: 1708 cu in (28L)
- Weight: 2 lb 1 oz w/frame (935g), 1 lb 14 oz w/o frame (850g)
- Main Compartment Capacity: Approx. 23L
- Total Pack Capacity: 28L
Main Compartment Dimensions (fully loaded with one full roll):
- 60 cm tall
- 23 cm wide (measured at the centre of the pack)
- 17 cm deep (measured at the centre of the pack)
Exterior Storage:
- Front side pockets: Approx. 1L each
- Waist pockets: Approx. 0.5L each
- Rear bottle pockets: Approx. 1L each
- Rear stow pocket: Approx. 1L depending on main compartment load Sizing
SM/MD:
- Waist: 27″-38″
- Torso: 15.5″-18.5″,
MD/LG:
- Waist: 29″-42″
- Torso: 17.5″-20.5″