The LSRK linear strip retrofit kit quickly and easily attaches to existing housings, making it a stylish, simple way to convert fluorescent fixtures to LED.Labor-saving pre-wired assembly that's ready for installation, Two widths available to fit most 4-4.25" or 5-5.25" channels, Optional snap-on lens with endcaps can be factory or field-installed, Occupancy and daylight sensors available for both lensed and unlensed versions, Battery backup available for most configurations,