Stainless-steel water bottle has two openings: the small one up top has a ball-bearing to control water flow when you hold the bottle upside-down for Dog to drink (think hamster water bottle and you're on the right track). The second opening is larger to allow for filling and cleaning. You can also un-screw the whole top of the bottle, flip it over - and it's a cup! 

•  Stainless steel construction
•  BPA-Free 
•  16 FL-ounce Ball bearing water control for drinking and large opening for filling
•  Fits most standard cup holders 
• Comes with handy carabiner for easy carrying