Digital camera CCD or CMOS sensors are highly susceptible to reflections - this stray light can ruin your photographs! Rinsable Pre-Filter - this first line of defense in the multi-stage filtration system catches lint, pet hair, and other large particles so the filter made with HEPA media can do its job of capturing the smallest particles Charcoal Filter - this large, porous surface is the filter layer that absorbs airborne odors Filter made with HEPA Media - HEPA media traps up to 99.97% of dust and pollens down to 0.3 microns Ionizer - helps eliminate household odors and trap airborne dust, pollen, and germs Intuitive Controls - for easy one-touch adjustments 3 Speed Fan - easily adjusts for multiple levels of cleaning power Change Filter LED Indicator - no need for guessing - it illuminates when it is time to change the filter, made with HEPA media 7 Room Air Changes every 3 hours (based on a 12" x 12" room size); formula for the 3 Hour Room Air Changes calculation - ((51 x 60) / 1152) x 3 = 7.96 Manufacturer"s 2-year warranty