General
10
Products containing this symbol are operated
with direct current�
Products marked with this symbol have a socket
with negative outer conductor and positive inner
conductor� They should only be connected to
products whose plugs also have a negative outer
conductor and a positive inner conductor�
Devices with this symbol have an additional or
a reinforced form of insulation and comply with
protection Class II.
For indoor use only� Devices bearing this symbol
may only be operated indoors�
(dry environment)�