Manufactured in a Class 100,000 clean room, from USP Class VI virgin polystyrene. The filter membrane is Polyether sulfone (PES) material in 0.22Μm or 0.45Μm Pore sizes for rapid flow rate and low protein binding. Bottle top filters are compatible with 45mm neck bottles. The bottle top filters are sterile (gamma irradiated) and available in 150Ml, 250Ml and 500Ml sizes and are individually packaged in easy to open plastic bags with individually wrapped caps.