I wanted to leave a positive review for this product, to counter some of the negative feedback. I ordered the bowl a few weeks ago, and am really happy with it.
Yes, it isn't particularly large, but is as per the measurements on the page. It's quite deep, so holds more water than you might think at first. I own a Golden Retriever and, whilst I wouldn't feel happy leaving him during the day with just this bowl to drink from, it has proved fine to leave him with when he's in his crate overnight (it is mostly untouched in the morning, he doesn't tend to drink much because he's asleep!)
It clips nicely onto his crate, and is much easier to use than the screw plated bowl that I had previously.
The product is a great price, does the job, and I would recommend it. Just think carefully about the dimensions before you buy, versus when and how you want to use the bowl, and the size of your dog - and if necessary, buy two :)