USWE - Vertical Hydration Pack Premium fit and functionality for fast and extreme trails, the Vertical 4 Basic Pack is a high-ventilated mesh harness system allows for comfort and proper fit. Shoulder and chest straps allow for the perfect fit. Vertical™ 4L Basic does not include bladder system. A lightweight hydration backpack, the Vertical™ 4L Plus is designed for the performance-minded, multi-sport enthusiast. With 4 liters of storage capacity for both gear and hydration, the Vertical™ 4L Plus is essential for long days of adventure. The soft mesh and highly ventilated shoulder and chest straps come built in to the NDM™ 4-point harness system. This ensures the best fit offered across the market. Plus model includes the 2L Hydrapak Elite™ Bladder. Features: Weight: 295 grams, excluding bladder No Dancing Monkey™ harness technology Twin port exit for tube from Hydration compartment Reflective point at the front Ultralight mesh back panel Pole attachment system Multi size adjustable: M-XL (Chest 82-115cm) Unisex fit