Producător : Marquardt

SPST : single pole single throw
SPDT : single pole double throw
DPST : double pole single throw
DPDT : double pole double throw
 
 
For multipole switches:
3P : 3 pole
   3PST means 3 pole single throw
4P : 4 pole
   4PDT means 4 pole double throw
 
 
Contacts position:
NO : normally open contacts are operated to "make"
NC : normally closed contacts are operated to "break"
 
 
For switches with 3 stable positions:
SP3T : single pole ON-OFF-ON
DP3T : double pole ON-OFF-ON
Momentary action: the state of the switch will change only whilst the operating force is applied. When released the switch will return to its original state