Color Changing Combination Coalescing/Carbon Cartridge with auto shut-off valve. The two (2) piece coalescing filter/carbon cartridge filters out odors and potentially harmful VOCs. Features colormetric indicator for filter changes. Standard for the Aerosolv® Super System. Designed to comply with California's vapor emission regulations. Includes a check valve in the Carbon Cartridge to help prevent passive gas release. Filter life is 9 months or 2,250 cans with changing the Carbon Cartridge (upper portion) twice. Cartridge life is 3 months of 750 cans; more frequent change-outs may be necessary based on use.