The box AK 10 User Manual page 11

Safety instructions
NOTICE!
Power supply
Before connecting the device, ensure that the input voltage (AC outlet) matches
the voltage rating of the device and that the AC outlet is protected by a residual
current circuit breaker. Failure to do so could result in damage to the device and
possibly injure the user.
Unplug the device before electrical storms occur and when it is unused for long
periods of time to reduce the risk of electric shock or fire.
NOTICE!
Risk of fire due to incorrect polarity
Incorrectly inserted batteries may destroy the device or the batteries.
Ensure that proper polarity is observed when inserting batteries.
AK 10
11