I picked up one of these H2O4K9 water bottles today at the All About Pets Show in Toronto. It's stainless steel, which I prefer to aluminum because aluminum does leech into the water. The stainless steel is very thin, which keeps the bottle as light as possible. It has a wide enough neck that you can put ice into the water on really hot days. The lid is a screw cap with a silicone gasket, and it turns into a small water bowl for the dog. I wish they made a bigger size so I could use it for two big dogs. I do appreciate how it's just a bottle with a cap that doubles with a bowl. This is such a superior design to anything else I've seen on the market. No need to fuss around with a collapsable bowl, etc. Just pour the water into the cap, and let them drink. Then pour left overs back into bottle, tigten cap, and it can go back into your backpack. No fuss, no mess.
We used it today on our dog park adventure, and we give it an enthusiastic 2 thumbs up.
So if you have a pooch of your own, or if you are looking for a gift for someone with a pooch, this is a must have accessory as we move into the hot summer months!