Featuring a wide base for greater stability, these borosilicate glass flasks have a serial number and a marking area. Its design addresses the needs of smaller volume vessels. All sizes are made to meet the requirements of ASTM E 237. Calibrated "to contain" (TC) at 20°C and supplied with glass Standard Taper stopper. 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.