This is a beautiful Iris Blue ombre set will be perfet for your Cavlaier (or any small-medium sized dog).
Each One Dog Set includes 1 water bowl and one food bowl
Size for one dog: Water 2 cups +, food -1 cup.
Bottom: Footed water, flat food
Generally, if you have one dog, either cavalier or cocker (or a similar sized dog), a 2 cup water bowl will likely last all or most of the day..
There are a number of variables that may affect the amount of water a dog drinks, so this is not an absolute for all dogs but a good general rule. My food bowls hold a comfortable cup of food. That would cover nearly all dogs of this size as well.