This two-port polypropylene Quick Filling/Venting Closure forms a convenient fluid transfer system with 1/4 inch tubing. Socket fittings in the polypropylene cap with TPE gasket have internal valves that seal when a tubulation fitting is removed so that container seal integrity is maintained. Ported 83B closure features quick disconnect fittings and inside/outside barbed tubulations. Closure is autoclavable and is excellent for use in vacuum systems with Nalgene Heavy Duty vacuum carboys and bottles and 180 heavy-wall tubing. NOTE: Not recommended for vacuum use with lighter weight containers. Fitting-to-socket seals will not hold vacuum after multiple autoclavings. Autoclavable. Tubing bulkhead fitting: 1/4 inch. Number of sanitary ports: 2. Closure size: 83B. Sold individually. Nalgene #: 2158-0021.