The Xiaomi Mi Vacuum Mini HEPA Filter is made from highly densified materials, designed to filter out any dirt in the air during usage. The HEPA filter can securely keep the air clean during vacuuming. Easy to install and clean, these HEPA filters are also washable. This affordable filter comes in a family pack of 2, which should be changed every 2-3 months for better suction performance. The HEPA filter can be re-installed before or when it's completely dry.