Here's a pic
I bought this to use for Neiko while we are doing search and rescue. It is not cheap - around $17. It's not that light weight either. However, with normal water bottles, we were wasting a lot of water because it would spill on the ground and such. The design of this is nice because we only use up what he needs at the time so we don't run out during searches. It fits nicely in my back pack as well because it is narrow and tall.
I did find though that Abbie, who is a very soft dog, was afraid of it at first. It took a little while to get her used to the rolly ball at the end of the bottle.