PUREMATE PM501 True HEPA Air Purifier 3 in 1 solution for every environment. Effective agaisnt Dust, Smoke, Allegens, Cooking Odours, Pet Dander & Hair. Featuring a multi-layer air purification system specifically designed to help improve air quality for allergy sufferers, those with sensitivity to airborne particles or simply for general air cleanliness. This efficient air purifier can capture up to 99.97% of dust and allergens with a Clean Air Delivery Rate of 42m³/h. Use the simple one button design to choose between 2 power modes with whisper quiet operation. This versatile air purifier is perfect for bedrooms, home offices & living areas. HOW TO REPLACE THE FILTER: The Filter Reset LED flickering continuously indicates it is time to replace the filter. Turn the air purifier upside down. Remove the screw cap, then lift off the base. Remove the dirty filter and recycle. Insert the new filter into the air purifier. Reassemble the base and fasten with the screw cap. Turn the air puri