It comes with a little mallet, much like that found on a xylophone, which allows the user to know how much water (if any) is in the jug based on the tones made by the hammer when it strikes the body and the handle.

When the two tones are the same, the pitcher is empty, yet the fuller the jug is the higher the note emitted from the body, while the tone from the handle stays the same.

I guess it has some practical advantages for the visually impaired, or just as a cool little trick to know whether there’s water available without lifting the lid.

It’s a concept design by Petit Invention.