This symbol means that this unit is double insulated.
AM/FM STEREO RECEIVER RX-1052
> 10 cm
STANDBY
> 4 in
TREBLE
SPEAKERS
TUNING
BAND
A
TUNE/
BASS
PRESET
MONO
MEMORY
B
> 10 cm
> 4 in
> 10 cm
> 4 in
PHONO
CD
TUNER
TAPE
VIDEO1
VIDEO2
VIDEO3
VIDEO4
ZONE
SEL
> 10 cm
> 4 in