Here is an APA151 ANNUNCIATOR FOR DUCT PIEZO ALARM by System Sensor.
The APA151 piezo annunciator, which replaces the APA451 with a new, improved look, provides an audible alarm signal, a red LED to indicate alarm status, and a green LED to indicate power status.
It is intended for use with System Sensor 4-wire conventional duct smoke detector applications without a system control panel, to comply with NFPA 90A.
New in original package, light wear to package. [O1az]
Shipping is by USPS First Class or Priority Mail, 3-7 day delivery time.