SEBO K-Series Service BoxThe SEBO K Series Service Box includes 8 AeraPure filter bags, a pre motor filter, and an exhaust filter. The electrostatically charged filter bags capture dust as the first stage of anti allergy filtration. The pre motor microfilter protects the motor by trapping fine dust, while the exhaust filter retains the remaining microscopic particles. We recommend replacing the filters after every 16 vacuum bags or approximately every two years.