Round Filter with Rubber Mouthpiece for Collins DC-2 50/CSKit Round Filter with Rubber MouthpieceSKU: 5556548$143.75PriceShipping Terms PolicyQuantity*Add to CartFilter Specifications Bacterial Filtration Effeciency 99.99% Viral Filtration Effeciency 99.99% Dead Space Approx. 35ml (cc) Resistance 0.23 cm H2O/L/sec approx. Material K resin case Electrostat® fitrate medium Nelson Labs Test Results