ART Pro Audio SLA2 - 200W Power Amplifier - Manual (Page 6)

6
SECURITY COVER
For commercial installations it may be desirable to set the gain controls on
the power amp, and then make them inaccessible to non-qualified operators.
This can be accomplished by using the Security Cover Plate which is included
with the SLA-2.
Simply set the channel attenuators to the desired gain settings, then press the
knobs into the chassis until they lock in their recessed position. Then remove
the two small phillips head screws, one on each side of the two channel
attenuator knobs. Use these same screws to attach the security cover plate to
the front panel, thereby covering the two channel attenuators, making them
tamperproof.
See diagram below