The System Sensor 54TP91 is a 12/24 volt speaker strobe that provides a clear temporal pattern and voice evacuation for fire alarm systems. It has a maximum sound output of 90 dB at 10 feet and a selectable candela range from 15 to 110 candela. The speaker strobe is made of durable ABS plastic housing, has a universal mounting plate, and includes screw terminal connections. It meets UL standards 1971 and 464 and is compatible with fire panels using System Sensor synchronization protocol. With its adjustable volume control and power taps, the 54TP91 provides flexible installation for indoor fire alarm notification.