I was so excited to see a sports cap (FINALLY!) from Waterdrop, as I was tired of screwing and unscrewing the lid off during ballet class. I wished there had been a white version, as the black and grey don't go with some of my lighter pastel bottles, but anyway I bought 3 in black and grey. It's only sort of okay - the water gets air bubbles when you are drinking from them, even if you tip the bottle up a long way and even if the bottle has plenty of water in it. It could be a lot better. So one star. Only I should mention that it did actually fit some (not all) of my older bottles.