With sealed-in fritted glass disc, these low form Gooch crucibles, made of borosilicate glass, are for analytical work involving precipitation, drying, and weighing. Fine (F), medium (M), and coarse (C) porosities available. Note: Avoid sudden temperature changes when heating or cooling. Scientists rely on the expertise and artistic skills of Wilmad-LabGlass' engineers and glass specialists to manufacture NMR and EPR consumables and laboratory glassware of the highest quality. Used daily in academia, healthcare and chemical, petroleum and other industrial applications, Wilmad offers 7000+ items as part of their standard catalog as well as custom fabrication for individual glassware, glass repair services and OEM glass parts.