Struggled a bit to open the first toy, now it rolls I got used, it makes a little noise, that's all that we could in a pinch reproach. Otherwise great economic, personal area 6 drops of essential oil, whenever I put water level (or 1 cup, which is supplied), I completely emptied once, the water was murky and to spend a bit of a cotton swab on the small "filter" the bottom. In short as long as it lasts.
