Volt 75 Hiking Backpack Tar Black. Imagine a backpack that provides all of the essential features for any backcountry trip and offers an incredibly versatile fit in a complete value package. The Volt/Viva Series delivers just that. The AirScape back panel provides ventilation with a harness that can be easily adjusted to fit different torso lengths. The pack series also offers the Fit-on-the-Fly hip belt for a perfect fit with comf