Material: DURAN ® glass, borosilicate glass 3.3. Autoclavable: yes. Flat flange lid for closing flat flange vessels. Due to the standard ground joint, suitable for combination with other ground joint components (e.g. dropping funnels, coolers and stirrer shafts). Also suitable as a replacement lid for Witt filtration devices. For chemically and thermally demanding processes Pressure- and vacuum-resistant due to the geometry and the solid wall thickness Note: at a maximum operating temperature of +250 °C and the respective permissible operating pressure, the temperature difference in the glass wall of the flat flange lid must not be more than 30 °C. Flat flange lid DURAN ® centre neck with NS