Extend the life of your Mi Vacuum Cleaner G10 or G9 with the Xiaomi Mi Vacuum Cleaner G10/G9 HEPA Filter Pack. It features 2x Pre-HEPA filters and 1x HEPA filter made out of highly densified materials, which allow for securing of clean air during vacuuming. The pre-HEPA filter works as the first barrier to stop big particles, it also helps to lengthen the lifetime of the HEPA filter. Pre-HEPA filters are recommended to be changed every 9 months.