As someone who does a lot of trail running, this hydration vest has been an absolute game-changer! The 5.5L capacity is perfect for longer runs - it's enough space for essentials without being bulky or heavy (only 250g for the pack itself!). The included 2L bladder is great quality with a bite-and-pull valve that doesn't leak, and you get two 250ml water bottles that fit perfectly in the front pockets. What I love most is how comfortable it is - the adjustable waist and chest straps plus the breathable mesh back mean no bouncing and no chafing, even on rough terrain. There are six exterior pockets that are super handy for storing my phone, keys, energy gels, and other small items I need quick access to. The vest-shaped design distributes weight evenly, so it doesn't feel like you're carrying much even when it's fully loaded. Whether you're training for a marathon, hitting the trails, or just want to stay hydrated on long hikes, this vest makes carrying water and gear actually comfortable!