Martin Audio C8.1T - Manual (Page 9)

The input and loop connectors must be fireproofed using the steel
cover and screws provided. This cover has a 0.75” (19mm) knockout
and a clamped cable entry.
Ceiling loudspeaker rear can
– fireproof steel cover fitted
Step 7
Fit a steel safety wire between its rear can safety tag and a suitable
overhead supporting structure to provide backup support in the event
of ceiling damage.
Safety tag location
All material © 2007. Martin Audio Ltd. Subject to change without notice.