From the manufacturer

Designed with Mountain Bikers in mind, the Hip Pack + Double Bottle Base optimizes storage and hydration on the trail. Magnetic-mechanical Twist bases keep your hydration secure and within reach. Magnetic self-sealing Hermetic Dry Bag keeps your phone and other valuables 100% protected from water, dirt, dust, and sand. Extra storage is also offered through a large and compressible compartment, with flexible straps for attaching jackets and more - as well as two additional pockets for storing keys and small essentials. 

Features

• 100% Waterproof dry bag compartment
• Two TWIST bases
• TWIST 450 Bottle in the color Smoke
• Large, compressible storage compartment
• Flexible straps
• Two small side compartments
• Adjustable hip straps
• Compatible with all TWIST bottles

Specifications

• Hip Circumference: 76-140 cm
• Weight: 500 g
• Volume: 2.5 L