Plug-in germicidal light bulbs offer an easy way to rid an area of germs with a convenient plug-in base. These bulbs use phosphors and a quartz glass envelope that eliminates germs, yeast, viruses and mold easily and effectively. Germicidal bulbs generally give off minimal actual light, and invisibly cleanse the air or water, destroying harmful bacteria. Plug-in germicidal bulbs are user friendly - simply plug in the two or four pin bulb to begin utilizing its useful and powerful properties.