Bulk packaged with filter membrane type and membrane porosity printed on each filter. Polypropylene microfiber pre-filter layer to improve filtration of particulate-laden fluids. Performance – High flow rates and low absorption membranes for minimal sample loss. Simplicity – Color coded outer ring allows easy identification of membrane and filter media type. Each unit is clearly marked with an identifying code to denote pore size and membrane material. Strength – Bonded outer ring on housing provides strength under higher working pressures for high performance needs Efficiency – Integral polypropylene pre-filter for high flow rates and fast filtration Quality – Manufacturing process certified to ISO 9001 standards