hipster 4l incl bladder backpack. the hipster4 is a reduced-to-the-max, super-light, super-slim hipbag. essential features such as a racelite airflow vented back, hydration system compatibility, a auto compression hipbelt and hip fins with zipper pockets make it awesome for a quick blaze around the trails or a full adrenaline-fueled day out. comes with a 1.5 ltr. widepac bladder from source.