FOCUS Enhancements FS-2 - Manual (Page 2)

Symbols
On the FS-2/2E Unit
The lightning flash with arrowhead symbol, within an equilateral
triangle, is intended to alert the user to the presence of an
uninsulated Dangerous Voltage within the product’s enclosure that
may be of sufficient magnitude to constitute a risk of electric shock
to persons.
Caution
For continued protection against fire, replace only with fuses of
correct rating, as listed on the rear panel.
Caution
TO PREVENT THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE
COVER (OR BACK). NO USER SERVICEABLE PARTS INSIDE. REFER
SERVICING TO QUALIFIED SERVICE PERSONNEL.
In the FS-2/2E Documentation
The exclamation point within an equilateral triangle is intended to
alert the user to the presence of important operating and
maintenance (servicing) instructions in the literature
accompanying the device.