the hipster4 is a reduced-to-the-max, super-light, super-slim hip belt with a racelite airflow flow system vented back and hydration system compatibility. 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.