The Aqua Pure 6899831 Filter Coupler can be used to connect any 2 Aqua Pure 9 3/4" filter cartridges to fit any 20" length housing. Couplers create a consistant flow and prevent leaking that can occur when 2 filters are stacked in a 20 inch housing. 68998-31.
Because this coupler pushes into the filters to create a seal, it will only work with polypropylene filters. This coupler cannot be used with filters that have plastic endcaps.