https://www.asmag.com/project/resource/index.aspx?aid=16&t=secutech-made-in-taiwan-products-and-solutions
Product Info
Gianni GD840SC Electromagnetic Door Holder

Gianni GD840SC Electromagnetic Door Holder

GIANNI INDUSTRIES INC.
Region: Taiwan
Update: 12/28/2015
Key Specifications

- Wall Surface Mount

- Operating Voltage: 24VDC (12VDC is available by special order)

- Current Draw: 60mA / 24VDC

- Push-off Button: Push to cutoff the power and then the magnetic door holder is inactive 

- LED Indicator 

- Holding Force: Up to 80 lbs

- Anti-residual magnetism function   

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