I have two Search & Rescue dogs that each wear Front Range day packs, one Medium and one Large. We work in the Rockies, where water is readily available, but there can be long stretches between streams or lakes. Each dog carries one of these in their pack in case we need a water break. The bottle fits perfectly in the pack pocket, and then we counter-balance with food and collapsible bowls on the other side. Perfect solution, couldn't be better!