The Trion RX HEPA Air Cleaner is a portable room air cleaner. It is ROUGHLY 2 feet tall and 14 inches square. This unit contains a prefilter, HEPA filter and charcoal after filter. Maintenance on the Trion RX HEPA Air Cleaner consists of washing out the prefilter on a monthly basis, replacing the charcoal filter every 3 months and replacing the HEPA filter every 12 months. The charcoal filter must be replaced more often if you have a heavy smoker in the space. The BRAND NEW HEPA filter now available replaces all 3 of those items and needs replaced every 3 months. This new style HEPA filter has a prefilter and charcoal filter built into in so maintenance has been reduced to replacing the entire cartridge every 3 months.