XG4 Flat Cable Connectors Omron Electronics XG4 Flat Cable Connectors are industry-standard circuit board connectors that conform to MIL standards. XG4M-U connectors feature lock levers on the strain relief/socket instead of on the plug, saving 24% of space. The XG4C space-saving box-type plugs are also available. Omron XG4 Flat Cable Connectors can be used with XG5 IDC connectors for discrete wires, XG8 original PCB plugs, and XG2 IDC bus connectors for PCBs. The original PCB plugs (XG8) and box-type plugs (XG4C) can be locked using external XG5Z and XG4Z lock levers.