https://www.asmag.com/project/resource/index.aspx?aid=16&t=secutech-made-in-taiwan-products-and-solutions
Product Info
P&H HS52 Smoke & Heat Detector

P&H HS52 Smoke & Heat Detector

Shenzhen P&H Electronic Co., Ltd.
Region: China
Update: 05/09/2012
Key Specifications
Features:

* AC 120V/230V powered with 9V backup battery

* Fixed temperature 57 degrees Celsius, 137 degrees Fahrenheit heat sensor

* Interconnects can be up to 40pcs detector

* Safe AC direct wire

* Designed to comply with EN-54 standards

* Easy-to-Read LED indicator

* Low battery indication

* Extended warranty

* Dimensions: 124mm(Dia) by 40mm(H)

https://www.asmag.com/project/resource/index.aspx?aid=16&t=secutech-made-in-taiwan-products-and-solutions