According to the manufacturer, the Mova 600 is IPX6 rated, and there's a nice photo of the mower being hosed down.
In German:
https://de.mova.tech/products... ("Wasserdichte Konstruktion" suchen) or in French:
https://fr.mova.tech/products... (search for "Étanchéité")
Look at the page below to understand the meaning of IPX6.
In German:
https://de.wikipedia.org/wiki...or in French:
https://fr.wikipedia.org/wiki...So, in theory, it should be waterproof... but that's just the theory! And over time, it's not uncommon for seals to wear out or for something that used to be watertight to no longer be really watertight.
In my opinion, the best thing to do with all mowing equipment is to let the grass dry and then use a simple brush to remove the dried grass from your mower. In fact, it's better to mow in the afternoon to avoid the grass getting wet and sticky, so there's no need to clean the mower regularly.
