Every detail of the PX 3.1L has been crafted with usability in mind. The front section features two hydration pockets for 500ml flasks, each secured with elastic cords and auto-locks, while two large feed pockets offer generous storage for energy supplies. A 100ml safety pocket on the shoulder, complete with whistle and internal cord ring, keeps your critical items close at hand. Meanwhile, the vertical pole attachments allow for smooth storage and access mid-run.

Round the back, the PX 3.1L doesn’t compromise on utility. A 500ml horizontal pocket with elastic cord and velcro lock gives you quick access to your rain shell without removing the vest, while a 300ml bottom pocket keeps safety items like gloves or a headlamp easily reachable. These thoughtfully designed pockets combine with the breathable honeycomb mesh to ensure comfort, airflow, and practical storage.

Instinct’s signature double “S” elastic lacing system allows on-the-fly adjustments, so the vest moulds perfectly to your body as you move. Whether you're running fast, climbing hard, or pacing a long event, the PX 3.1L offers a secure, minimal solution that keeps everything you need close, without ever getting in your way.

The Instinct PX 3.1L is designed around a high-sitting, non-compressive structure that hugs your torso without restricting your breath or movement. Its layout ensures that all essential items such as hydration, nutrition, rain gear, safety equipment, are accessible without removing the vest. The front and back pockets use elastic compression cords with auto-lock mechanisms, so gear stays firmly in place while you move.

Its fit is fully adjustable via front sternum straps and a double “S” lacing system on the sides, meaning you can fine-tune the fit on the go. The use of lightweight, breathable mesh throughout keeps you cool, even during intense efforts. Everything is streamlined for one goal: maximum function with minimum distraction.