Sharp IG-CL15U Ultra High Density Plasmacluster Ion Generator - White Ultra high density plasmacluster ion generator recommended for spaces up to 161 sq. ft. Plasmacluster technology effectively restores natural balance of ions in the air while pre-filter traps dust, dirt and other airborne particles Simple one-touch operation allows user to choose among 2 fan speeds (low and high) Library Quiet operation is ideal for bedrooms and living rooms (Noise level is 29 dB on low and 40 dB on high) Long life Ion Engine (up to 19,000 hours use without performance decrease)