Steren RM-KID Manual De Instrucciones página 41

Volume lock
You can lock the volume and mute buttons by following these steps:
18
1
CH
V
3
2
1. Press the power button and mute at the same
time for 3 seconds until the LED lights.
2. Enter 9991 code, the LED will light.
3. Press "V +" to lock the volume and mute buttons,
the LED fl ashes twice and then go off indicating
that it has successfully blocked the volume.
4. To unlock the volume, repeat the same steps
but this time press "V-" after entering the 9991
code.