1. wound string filter cartridge media : PP( Polypropylene), cotton; 2. length: 5'', 10'', 20'', 30'', 40'' ; ... length : 10'',20'', 30'',40'';2. wound string filter cartridge media: pp, cotton ;3. micron : 1um, 5um, 10um, 20um, 30um, 50um ... outer layers and tight inner layers offers effective depth filtration; d. various filter media fit with various applications.