4*5 SCM keyboard Matrix Array keyboard Membrane external expansion keyboard
 
4x5 matrix keyboard:
Panel Size: 75*85mm. 
Length: 18CM. 
Insulation Resistance:100M Ω 100V. 
Withstand Voltage:250V Rms.(50-60Hz lmin) 
Storage Temperature: +15°to +35°°C
Storage Humidity:70-90.