Limit switches serve as the mechanism that tells the computer the limits of the CNC machine. When one of the axes moves to an axis limit, the switch is activated and the machine stops. 

For limit switch use for CNC machines, it will be connected to signal voltage levels like 5v. Also you have the option of using this switch as an interlock to turn off something when a door is opened.

• Current Rating: 1A @ 125V AC
• Dimension: 12.8 x 6.5 x 5.8 mm