You are purchasing one air purifier UV light bulb 10,000 hour long life lamp 1 year warranty includes free gloves for handling UV hot cathode germicidal UV bulbs (UV-C), are low-pressure mercury arc lamps that are the most effective tool for eliminating microorganisms such as virus, bacteria, mold and yeast in the air and impurities in water. Produces UV-C (253.7 nm wavelength) radiation (harmful to eyes and skin). This ultraviolet purification lamp is instant starting and utilizes a coil filament, which operates hot. The UV lamp life is governed by the life of the electrodes and is affected by the frequency of starting. This germicidal lamp is well-suited for the following applications that require UV-C intensity: Applications: Well water surface water municipal water food service/processing hospitals aquaculture electronics pharmaceuticals hotels water bottlers laboratories marine and more.