Medify takes home air purifiers to the next level. We only use medical grade True HEPA H13 filters in our models. HEPA Type and lower grades of True HEPA filters don't stop smaller particles, like Medify HEPA H13 filters. At Medify, we aim to provide better and cleaner air for our customers to help them live longer healthier lives. We accomplish this by using the highest quality medical grade True HEPA H13 filters. The industry bases performance on a metric called CADR (clean air delivery rate). What they don't explain is that a poor-quality filter allows air to blow through a fan faster. So a company can claim to cover more square footage without providing the quality you need and deserve. The same unit with a medical grade filter will cover approximately 15% less square footage, but the quality can be many times better.