1This CNC engraving machine controller is specially designed for Mach3 system 2Easy to use, no need to install any software or drive, connected by USB port and the cable can be stretched to about 3 meters 3Integrated 21 function keys including emergency stop, cycle start, spindle on/off and so on 4The exterior housing is water-resistant and can guarantee normal operation against dirty or oil 512*12mm buttons ensure that your finger will not interfere with the adjacent buttons Features: This CNC engraving machine controller is specially designed for Mach3 system.Easy to use, no need to install any software or drive, connected by USB port and the cable can be stretched to about 3 meters. Integrated 21 function keys including emergency stop, cycle start, spindle on/off and so on.The exterior housing is water-resistant and can guarantee normal operation against dirty or oil.12*12mm buttons ensure that your finger will not interfere with the adjacent buttons. Specifications: Compatibility: For Mach3 only Connector: USB Size: 20.5*8*2.8/8.07*3.14*1.1in Package Includes: 1 x Controller