The LED-ARFK4 is an Architectural grade, LED Recessed Downlight Retrokit and is available with multiple Trim styles. It is designed for use with existing Lum-Tech 4” Architectural Incandescent, Fluorescent and Metal Halide Housings. It is also compatible with most 4” architectural housings measuring at least 4-7/8” high with an inside diameter between 4-1/2” and 5” (See Housing Compatibility section).