This Harmony plastic blanking plug is compatible with Harmony XB4, XB5 and XB7 pushbuttons with flush push.This plastic blanking plugis designed as an option to fit with your pushbutton units when no function is needed for machine to operate.It is compatible with standard 22mm XB4, XB5 and XB7 control and signaling units.It has a plastic bezel, this makes it ideal for applications requiring good resistance to chemical agents and/or double electrical insulation.It is designed to fit with a standard 22mm control and signaling units, ensuring compatibility when installing in pre-existing machinery.