At one point, you start to get fed up with juice stains, milk drips and sticky messes randomly all over your floor. Am I right? Well, once we got to this point we looked deeper for a better, less leaky sippy cup. Just like any other sippy cup, it will leak but ONLY if it has force behind it. There are zero issues of leakage while holding the cup upside down or on it's side. Even a short drop on the floor won't make it drip. The only time it drips is if it falls from a long distance. You can shake that cup like there is no tomorrow and you will still not get a drop spilled out. The cup's twist on top is made of a hard plastic, not a rubbery substance. These cups are exactly the same as the girls cup, just different colors. I recommend you use these cups rather than any other sippy cup for the baby you care for. It saves a lot of time and a lot of messes. The price is not high as well. Some come in 2 packs rather than just the single cup. I hope this helps!