Description_x000D_ General description_x000D_ Filter type HA, 0.45 μm pore size, is designed to give complete retention and maximum recovery of total coliforms and fecal coliform bacteria. Complies with applicable U.S. EPA Standard methods and ASTM specifications for membrane filters used for drinking water analysis._x000D_ Filter type HC, 0.7 μm pore size, is designed for improved recovery of stressed fecal coliform organisms, especially those found in chlorinated effluents. The larger pore size permits faster filtration if the water sample has a higher particulate burden._x000D_ Both filters are cellulose acetate/cellulose nitrate mixed esters._x000D_ S-Kit includes filter membrane plus absorbent pad, sterile, individually sealed, packed in 100′s in dispenser tubes._x000D_ S-Pak includes filter membrane, sterile, individually sealed.