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Coway Mighty Air Purifier with True HEPA and Eco Mode 空气净化器 for just $136.85 shipped (regularly $252.99).

This air purifier captures and reduces up to 99.7% of particles in the air including allergens, pollutants and more. It has a sensor that automatically adjusts the fan to help filter the air more when more particles are detected. Plus, when it does not detect any particles for 30 minutes it will automatically turn off to save energy. It includes washable pre-filters, an odor filter and a HEPA filter.