Can-Filters® knows carbon, and brings that knowledge and experience to give you full odor removal in all of your hydroponic applications. All activated carbon is not created equal, and each type of application requires careful consideration to have a full 99.5% odor removal efficiency. With Can-Filters® you can be assured that the proper Virgin Activated Carbon has been selected for the job and that the CFM has been mathematically calculated to give a .1 second contact time with a Pressure Drop of 180Pa/.75wp at Max Cfm. This contact time is essential for true 99.5% efficiency, and can only be acquired with a proper 2.5" carbon bed width and a heavy over all carbon weight. All Can-Filters® come with a top quality pre-filter. With this and the large carbon mass of our filters you will enjoy a true 12 to 18 months of maintenance free odor removal from our complete line of filters Max cfm: 200/350m³/h @ 0.1 sec contact time Recommended Max Airflow: 340m³h Prefilter: Yes Flange: 6 & 8" Dimensions: (with pre-filter)