For your own safety

See also:

Activating HDC
Press the button; the LED above the button lights up. ...

Selecting the distance
Selecting the distance ▷ Press the rocker down briefly: Increase the distance. ▷ Press the rocker up briefly: Decrease the distance. ▷ Press the rocker down briefly: Increase ...

Adjusting the volume
Turn the volume button while giving an instruction until the desired volume is set. ► The volume remains constant even if the volume of other audio sources is changed. ► The volume i ...