Acoustic Research HD510 Manual De La Instalación Y De La Operación página 4

The lightning flash with arrowhead symbol, within an equilateral tri-
angle, is intended to alert the user to the presence of "dangerous volt-
age" within the product's enclosure that may be of significant
magnitude to constitute a risk of electrical shock to persons.
The exclamation point within an equilateral triangle is intended to
alert the user to the presence of important operating a maintenance
(servicing) instructions in the literature accompanying this product.
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