This replacement uv-c bulb is 3.5-watts and eliminates over 98% of targeted airborne bacteria. uv-c light is highly effective at penetrating thin-walled germs like viruses and bacteria. the light alters the genetic structure of the germ and they die. it is suggested that the bulb be replaced every 6-8 months depending on use. fits the following models: gg1000, gg1000ca, ggh200.