Coway Mighty air purifier is $50 off today. The True HEPA purifier uses a four-step filtration system to clean the air—from pet dander, dust, mold particles, etc.—and reduce odors in a room measuring up to 361 square feet. A built-in sensor registers the air quality of the room, alerts you via a LED light, and will automatically adjust its power based on the readings. There are three fan settings and an eco mode that shuts the purifier off after 30 minutes if no air pollution is detected. It's also got a timer that you can set for 1, 4, 8, or 12 hours and will alert you once you need to change the filter. $180 (was $230).