Consumers who have been familiar with air purifiers must know that the most essential "haze removal" component in all filtration type air purification products is the HEPA filter, also known as the High Efficiency Particulate Air Filter. Little did they know that HEPA also has different levels, for example, LIFAair's new LA500 purifier has a HEPA level of 12. The difference in purification ability of different levels of filters has a direct impact on the purification ability of PM2.5.