• Single feed through: This is a basic type of terminal block having one input and one output contact. They are used for wire-to-wire connections where the wire can be fed through one side and out of the other.
  
   
• Dual level: Also known as the double level or two tier, these terminal blocks consist of two levels of contacts. These fittings are used for saving space and simplifying wiring.
  
   
• Dual level bridged: These are also known as double level or two tier. These bridged blocks make use of a "bridge" for one level to another for increased circuit flexibility. These blocks consist of two levels of contacts and are used for saving space and simplifying wiring.
  
   
• Three level: Also known as three tier blocks, these terminal blocks have three level of contacts and are used for saving space and simplifying wiring.
  
   
• Three level bridged: These blocks are also known as three tier, and have three levels of contacts. They are used for saving space and simplifying wiring. The blocks make use of a "bridge" for connecting one level to another for increased circuit flexibility.
  
   
• Thermocouple blocks: These are used for connecting thermocouples.
  
   
• I/O blocks: It is used for providing communication between a controller, usually a PLC or IPC, and some type of sensor level devices.

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