This is the camelbak bumbag, note can carry pfd in it. 1.5ltr, additional Features: Paddle holster, safety whistle, water-friendly materials, Camel Clip™ bite valve positioner, stretch overflow storage, PFD compatible
Designed to carry: Inflatable PFD, waterproof electronics case, sunscreen, extra layer, snacks
Also saw this while looking around the site, compression combined with hydration