Features & details High Flow Bite-Valve: The 'Easy-Twist' mouthpiece doesn't leak, water flows fast and won't drip on your shoulder when locked, making it an ideal cycling backpack and water backpack for running, skiing, snowboarding, and trail running Taste-Free Hydration Bladder: Made from medical grade materials, the water bladder is free from BPA and PVC. There's nothing worse than a plastic taste in your water, this bladder keeps your water tasting fresh, all day Multiple Storage Options: Vibrelli's hydration backpack design has intelligent storage options and pockets without being bulky Comfortable & Lightweight: Weighing just 14oz (415g), this hydration pack is feather-light, streamlined, and easy to adjust, it's the perfect adult and kids hydration backpack as it adjusts to most body sizes