The unique shape offers maximum interior clearances for more or larger contents without further crowding the benchtop. The thick walls ensure a rugged shatter resistant unit.The top section can be lifted off using the large ribbed knob at the top center. A Neoprene O-ring offers a secure seal, which does not require grease, but is unaffected if grease is applied. A rigid, perforated polypropylene plate, 3.2 mm (1/8") thick supports the contents and leaves space underneath for desiccant. The plate is removable and can be replaced with Scienceware® High Heat Desiccator Plates (catalog numbers F42038-0140, F42038-0190, F42038-0230 depending on size) to support hot crucibles. Replacement parts are available. Per each Small footprint with 13% more interior volume than typical desiccator domes Glass transparent, shatter resistant polycarbonate upper section offers unobstructed viewing of contents Polypropylene lower section has excellent chemical resistance and can be used with incandescent crucibles supported on high heat plate Use with disposable or reusable desiccant (Scienceware® catalog numbers F42048-0065, F42048-0100, F42046-0000, F42045 series). Flange O.D.: 230mm ( 9 1/16") Inside diameter: 197mm (7 3/4") Plate: 190mm No.4 Overall height: 260mm (10 1/4") Clearance above plate: 157mm (6 3/16")