Excellent cups that don't leak and are easy to clean. Just make sure you put the valves back correctly after washing!
Best Sippy Cup Ever
I have tried them all, and these cups are my favourite. 99% spill-proof. I've been buying these cups for the past 3yrs. You just have to make sure you put the internal part together properly (which is quite easy) and away you go. Go in the dishwasher again and again, no dramas.