Click on the image to check the artwork
By certification 
Button optional:
1. Color: red, blue, yellow
2. Diameter: 25mm-35mm (can be customized)
3. Braille: with or without Braille
4. Voltage: DC 12V or DV 24V
5. Number and figure: -3, -2, -1.0.1.2 ... 60, door open, door closed, up arrow, down arrow, alarm, telephone, G, B, P, B, B1, B2, etc.
6. Material: The surface is stainless steel.
7. Service life: more than 3 million operation time
http://www.elevator-supplier.com/
