C-TEC AST 4-8 Way Sounder Controller (ZFP CAST only), needs CA739PSU, 4-8 way sounder controller specifically designed for use on a C-TEC CAST ZFP addressable fire alarm system, 4 or 8 monitored 12.5mA sounder circuits, 12.5mA per sounder circuit capacity when loop powered; 300mA per sounder circuit capacity when aux CA739PSU PSU is used