Also known as troffers, these lights fit most standard drop-ceiling grids, so they’re often used in indoor spaces such as offices and storage rooms. They can be hardwired to operate on any of the voltages listed. Solid lens are frosted and smooth or prismatic to disperse light evenly. With built-in LEDs, these lights last longer, are more efficient, and generate less heat than fluorescent lights. They emit a neutral white light often found in workspaces.