Button optional:1.LED : Red ,Blue,Yellow2.Braille: with or without braille3.Voltage: DC 12V or DV 24V4.Number & Figure :-3,-2,-1.0.1.2...60,Door open,Door close ,Up arrow,Down arrow,Alarm,Telephone,G,B,P,B,B1,B2, etc5.Material :Frame in ABS ,surface in Stainless steel .6.Life: more than 5 million of operation time,OMRON switch7.Reference : all elevator .
link:http://www.ds-elevators.com/ak-23a