Lume Cube - Lighthouse Diffusion Bulb Pack diffuses the output of your Lume Cube. In addition to providing a diffusion effect, the Diffusion Bulb spreads the beam out to the sides, creating an overall ambience. There are three different strengths in the pack, a light, medium, and strong diffusion, and each one attaches magnetically to the Light-House Housing (not included). Although you cannot stack one Diffusion Bulb on top of another, you can mount the Diffusion bulb on top of a color gel, warming filter, or even another diffusion gel.