The ECC-50DA(E) and ECC-125DA(E) units come standard with four onboard fully supervised speaker circuit zones, and are expandable to eight circuits when an optional ECC-CE4 module is added Main Features Supports both Class A (Style Z) and Class B (Style Y)Wiring Easy setup and configuration by using a simple, built-inWeb based programming utility on the ECC-50/100(E) Each unit includes four onboard fully supervised audio circuitsWhich are expandable to eight circuitsWhen an ECC-CE4 module is added Any combination of up to eight ECC-50DA(E)s or ECC-125DA(E)s per system for a total of 1100 watts of audio power and 24 speaker circuit outputs. UL2572 (Communication and Control Units Mass Notification Systems). Built-in power supply and battery charger that supports up to 35AH Sturdy, scratch resistant cabinet.