the packaging system for a sterile hydrocephalus shunt provides access to the valves of the shunt for air testing of the opening and closing pressures of the valves without compromising the sterility of the shunt . the packaging system comprises two nested plastic packs positioned around the shunt with access to the valves of the shunt being provided by an air feedthrough connector assembly which includes a bacteriostatic filter to maintain the contents of the packaging system sterile against contamination by the air used in the pressure testing of the valves . the bacteriostatic filter is impervious to bacterial contaminants but is pervious to air or gaseous sterilizing agents which may be passed therethrough .