Package contains 1 replacement filter and 4 pre-filters Recommended to replace filter every 6 months and pre-filter every 3 months for maximum efficiency, or more often depending on air quality & environmental factors Compatible with Hunter Air Purifier models: HP800, HP800BL, HP800WH, HP800GR Approximate Measurements: 18 x 2.5 x 18.75 inches This replacement filter value pack is compatible with Hunter HP800 Multi-Room Large Console Air Purifiers. This value pack includes four (4) pre-filters and one (1) filter. Crafted with precision and convenience in mind, our replacement filters are made from high-quality materials to deliver reliable performance. Take a step towards cleaner and healthier air by choosing our compatible replacement filter value pack for your Hunter HP800 Air Purifier.