First Ascent12L AR-X Hydration Pack

About

Go further, carry more. The First Ascent AR-X 12L Hydration Pack is a race-ready trail running vest designed for longer distances, endurance runs, and light fast-packing.

With a larger 12L capacity, it gives you extra room for hydration, gear, and layers while still maintaining a lightweight, body-hugging fit - perfect for when your runs turn into full-day adventures.

Product Features

• Hydration Ready: Compatible with a 1.5L bladder + front soft flasks
• Dual Front Bottle Pockets: Fits 2 × 500ml soft bottles for quick access
• 12L Storage Capacity: Ideal for longer runs, hikes, and endurance sessions
• Multi-Pocket Organisation:
  • 2 × front zip pockets
  • 4 × front nutrition pockets
  • 1 × rear zip pocket
• Layer Storage Compartment: Space for a jacket or extra gear
• Running Pole Holders + Detachable Quiver: Built for trail and ultra-distance runs
• Secure Fit System: Adjustable chest straps for reduced bounce
• Integrated Safety Whistle: Added safety for outdoor use
• Breathable, Fast-Drying Fabric: Keeps you cool on long efforts
• Race-Optimised Design: Easy-access layout for nutrition and essentials

Product Specifications

Capacity & Use

• Capacity: 12 Litres
• Best Use: Trail running, endurance running, hiking
• Product Type: Hydration running vest/pack
• Ideal For: Long-distance runs & outdoor adventures
• Gender: Unisex

Weight & Build

• Weight: ±220 g (ultra-light for a 12L pack)
• Material: Lightweight breathable technical fabric
• Design: Ergonomic, body-hugging vest fit

Hydration System

• Bladder Compatibility: Up to 1.5L hydration bladder
• Front Bottle Storage: 2 × 500ml soft flask pockets
• Bottle Security: Drawcord system to keep bottles in place
• Note: Bottles and bladder sold separately

Storage & Organisation

• 2 × front stretch zip pockets (secure items)
• 4 × front nutrition pockets (quick access fuel)
• 1 × rear zip pocket (essentials)
• Rear compartment for jacket/layers
• Running pole holders + detachable quiver included

Sizing (Chest Fit)

• XS: 78–85 cm
• S: 83–90 cm
• M: 90–98 cm
• L: 98–103 cm
• XL: 103–109 cm
• Warranty: 6 months

What's in the Box?

• 1x 12L AR-X Hydration Pack