This Harmony ZBY legend holder with blank legend and with bezel has black or red background.It is compatible with Harmony XB4 and XB5 push buttons and pilot lights.This legend holder allows you to customize the control unit with blank legend for custom engraving to support any desired marking.It is compatible with any standard 22mm Harmony control or signalling unit.It provides clear and resilient symbol marking on the label, with high contrast.