Isolated barriers series The apparatus of the voltage or current supplied to the intrinsically safe circuit is limited within a certain safety range  
 
59G Series 58G Series
  59GD 59GI 59GM 59GO 58GXT          
 
                     
  58GC 58GD 58GI 58GM 58GN 58GO 58GR 58GT 58GS  
 
  58GU