Refurbished Protect 7770i 

How does the Classic DualProtection filter differ from the Classic Particle filter?

Classic DualProtection filters feature a highly-porous, lightweight carbon mesh that is extremely efficient at removing both particle and gaseous (odors, exhaust, smoke odors, and chemicals) pollutants from the air.

Classic Particle filters are highly efficient in the removal of particle pollutants like pollen, dust, mold, viruses, and fine smoke particles.