The PureMate PM 520 air cleaning system has its efficient 5-stage filtering system. It’s quiet, easy to use and maintain with its unique 5-Stage filtering ability, it can cover a wide range of air pollutants. The PureMate PM 520 is suitable for rooms up to 600 square feet of in size which makes it perfect for most bedrooms. It stands 28-inches tall. The unit’s CADR (Clear Air Delivery Rate) is 110+ which effectively means it’s able to deliver 110 cubic feet of clean air per minute with 5 changes of air per hour. The PM 520 has 5 fan speed settings available. When set on low, the unit is impressively quiet at 20 dB (A). In fact most people won’t be able to tell its working if it weren’t for the large blue LED, and the cleaner doesn’t get much louder when the fan speed is set to medium. The air purifier now comes equipped with indicator lights that automatically blink when it's time to replace the Hepa Filter. No more trying to remember the last time the filter was replaced. A clean filter not only maximises the amount of dust and allergens captured but helps optimise the performance of the entire purifier. Special note: as part of our quality promise - every purifier we make is tested before it reaches you. If your reminder lights are blinking when you first turn on your purifier, simply reset the system by holding the UV button for at least 3-5 seconds or until the reminder lights stop flashing.