ZS5601 and 5121 are trusted product for speaker zone selection which had been used
for more than a decade.
They provide direct zone switching for single source PA setup via front panel switches or
through remote port connected to Amperes PM Series paging desk, or through Amperes
TD decoders when PD series of paging desks are used. Other made of paging consoles
are compatible with ZS provided they have negative triggering switching ports.