Leitz TruSens Replacement UV-C Lamp for TruSens Z-1000 Air Purifier. UV-C light reduces the growth of odour-causing microbes on the surface of the air purifier filter. Microscopic airborne organisms get trapped in air filters, which could multiply if left untreated. When bacteria and germs are exposed to the germicidal wavelengths of UV-C light, they are rendered incapable of reproducing and infecting. Indicator light on the air purifier glows red when it's time to replace the bulb. Compatible with Leitz TruSens Z-1000 Air Purifier. An important part of the air purification system, a UV-C lamp destroys germs and bacteria.