12 Inch Purifier Activated Charcoal FilterPurifier Activated Charcoal Filter is constructed with a 72 mm thick carbon layer. The 12" Flange in the carbon air filter can effortlessly remove odors, filter the dust particles and purify the air. If you use this filter with the 12" vertex blower, it provides you a clean and pure grow environment. Features: 12" Flange 18 months life expectancy of continuous use Maintenance of Free Design Effective operation with high safety Includes Cotton filter