Crivit HG07903A Bedienungs- Und Sicherheitshinweise Seite 60

Cleaning and care
Never use liquids or abrasive cleaning
agents as they could damage the product.
Only the exterior of the product should be
cleaned with a soft, dry and lint-free cloth.
Maintenance
At longer time the product is not used, take
out the battery and change it as described
in the chapter "Replacing the battery"
60 GB