Big Flow 4.5 Micron Replacement Water Filter Cartridges For Chemical Filtration Darlly new design high flow filter cartridge for chemical filtration The DLHFSeries filter cartridge is a new product developed by Darlly Filtration Equipment Co.,Ltd in Hangzhou China. It has a 6inch/152mm large diameter, and is coreless, single open-ended with an inside to ourside flow pattern. The large diameter with big filter area insures to reduce the number of filter cartridges and the