324-0074 is a yellow illuminated pushbutton switch cap designed for use with Dialight's 554 series switch bases. This 1/2" square cap is manufactured from high-temperature scratch-resistant plastic and is compatible with various 554 series switch configurations including momentary and alternate action switches with different contact circuits (SPDT, DPDT). The cap features a standard flange base design with T-1 3/4 lamp compatibility, allowing integration with incandescent or neon lamp assemblies. It is commonly used in industrial control panels, instrumentation, and operator interface applications where color-coded visual feedback is required for switch identification and status indication.