[Schneider Electric]

22 and 30 mm Most Common Complete Operators
   Class 9001 Type K, SK—30 mm and XB4-XB5 22 mm most common
   complete operators assembled with contact blocks and suggested legend
   plates. Start-Stop and Hand-Of-Auto are just a few of the configurations
   offered in this simplified quick selector.

16 mm Push Buttons
   XB6 16 mm Push Buttons, selector switches, and pilot lights with a plastic
   bezel are intended for machine adjustment and set-up, such as conveyor
   systems and measuring equipment.

22 mm Push Buttons
   XB4 22 mm Push Buttons, selector switches, and pilot lights with a metal
      bezel are designed for industrial applications. They combine ease of
      installation and robustness.
   XB5 22 mm is the plastic version of the XB4 unit and is particularly suitable
      for applications requiring a resistance to chemical agents and/or double
      electrical insulation.