International certifications: CE, UL and RoHS Washable pre-filter and high-efficiency HEPA filter captures almost all airborne particles Independent negative ion generator with UL certification With more than 3,000,000 ions/cm3 released Compared with other products with same size and it has higher efficiency as its direct and logical airflow routeway Fashion design and coloring makes it more suitable for homes and offices User-friendly handle on the top make it safe and easy for users to move it to anywhere they want Whisper operation is for good sleeping and 25% quieter than most same size units Three-speed setting (L, M and H) and three timer setting (2, 4 and 8 hours)