How do you improve on the award winning bübi bottle, with its unique feel and multiple uses, the sports cap, it was designed with the bübi bottle in mind, the cap is as unconventional as the bottle.The bübi cap, is leak resistant, yet, you can squirt liquid from the bottle, or sip on the nipple, to hydrate while being active, or just for convenience of not having to take off the cap to drink. As the liquid goes down in volume, the bottle scrunches flatter, why is that important, well, there is no air in the bottle and liquid is not sloshing, in your bag, on your hip or in your hand. It is truly as unique as the bübi bottle. Comes with one cap and 2 nipples.So much fun and useful