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 a handy carabiner for easy carrying.