Stormwater catch basin insert (CBI) maintenance kit - includes new non-woven polypropylene liner, and 3 cubic feet of activated cellulose treatment media. Clients use these for maintaining 18x24" and 20x24" CBI. Shipped in a single box. Simply remove the old liner and media and replace with the new materials. Support bars secure the liner to the frame. (Note a second box of media is recommended for 28" ODOT units.)