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PX 3.1L

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Introducing the PX 3.1L, the epitome of minimalist and non-compressive carrying solutions. At a feather-light 160g, this innovative gear redefines the way you transport essentials, eliminating the need for traditional packs or belts. The PX 3.1L is engineered for both road and trail adventures, perfect for distances ranging from a quick one-hour jaunt to a full marathon. Its unique design offers a harmonious blend of comfort, convenience, and functionality, setting a new benchmark in outdoor gear.

Product Features

  • Ultra-lightweight at 160g for minimal impact on performance.
  • Non-compressive and bounce-free for maximum comfort.
  • High-sitting design for immediate, easy access.
  • Adjustable front sternum straps and elastic side lacing for a custom fit.
  • Optimal pocket layout for intuitive access.
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Select Type: PX 3.1L
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Product Description

The PX 3.1L sits high on your body, providing immediate and easy access to hydration, nutrition, poles, and other necessities. Its adjustable front sternum straps and unique elastic side lacing system ensure a custom fit for almost any body type, allowing for unparalleled stability and freedom of movement. This design promotes unconstrained breathing and keeps your gear secure without compressing your torso.

Designed with an optimal pocket layout, the PX 3.1L ensures natural, effortless, and intuitive access to your items. The lightweight and breathable honeycomb mesh material enhances ventilation and sweat dissipation, maintaining strength and reliability. The PX 3.1L accommodates up to 3.1 litres of volume, efficiently organising your gear without feeling cumbersome or restrictive.

The front of the PX 3.1L features two 500ml hydration pockets with elastic compression cords and auto-lock mechanisms, allowing for quick and effortless access. Additionally, two extra-large 500ml feed storage pockets ensure you have enough fuel for the journey. A 100ml shoulder pocket equipped with a non-stretch internal cord ring and whistle keeps your safety essentials within easy reach. The front vertical pole attachment allows for convenient storage of poles on either side.

On the back, the PX 3.1L offers a 500ml horizontal pocket with an elastic compression cord and auto-lock, coupled with a velcro locking system. This design allows you to access your rain gear swiftly without needing to remove the pack. A 300ml bottom horizontal pocket with a snap button closure provides central access to your safety kit, headlamp, gloves, and arm warmers. These dorsal solutions ensure that all your gear is readily accessible and securely stored.

With its double “S” elastic cross-lacing system, the PX 3.1L enables on-the-fly side adjustments, ensuring a perfect fit and stability during your run. The elastic compression cords with auto-locks for the top and bottom back pockets add to the ease of access and security of your essentials. The PX 3.1L is the ultimate companion for any runner seeking a seamless, lightweight, and highly functional carrying solution.

  • Ultra-lightweight at 160g for minimal impact on performance.
  • Non-compressive and bounce-free design ensures maximum comfort.
  • High-sitting position allows for immediate and easy access to essentials.
  • Adjustable front sternum straps and elastic side lacing for a custom fit.
  • Optimal pocket layout for intuitive and effortless access.
  • Breathable honeycomb mesh for enhanced ventilation and strength.
  • Carries 2 x 500ml hydration, fuel, rain jacket, safety kit, phone, headlamp, and poles.
  • Front and back pockets with elastic compression cords and auto-locks for secure storage.
  • Front vertical pole attachment for easy pole management.
Delivery / Returns FREE UK Delivery orders over £30,00, Next Day Service + FREE UK Returns

Shipping Information - Details

UK Standard Delivery - This means that your goods will be processed as normal and shipped by Royal Mail 48. Ordered goods will usually arrive within 3 - 5 working days for most of the UK mainland. Baskets with a total value (before vouchers and promotional codes are applied) of £30.00 and over will qualify for FREE UK delivery.

UK FREE Delivery - to all of the UK on almost every product, as long as your total basket value is greater than £30.00 (delivery charges are applied to baskets with a total value of less than £30.00). - All FREE Delivery order will be sent via (UK) STANDARD SHIPPING (Royal Mail 48)

Need it Quicker? - Select DPD Next Working Day or Fast Delivery at checkout - Orders will be processed as normal and shipped by either DPD for Next Working Day service (excluding weekends) or the Royal Mail Tracked 24 service, ordered goods will usually arrive within (1 - 2 working days)


Return this item for free - If you change your mind on your purchase, you have a 30 days to return it for a refund or replacement subject to terms. All goods must be in new and unused condition and in their original packaging with all labels still attached

About Instinct

Born on the trails of the French Alps and race approved around the world.

Redefining a hydration pack comes from asking the right questions... introducing analytical observations & first hand experience in running the toughest conditions. At the heart of each revolutionary Instinct product is the desire to achieve a greater degree of function, accessibility and ergonomics; Total liberty of movement, zero obstruction and a second skin fit.