These borosilicate glass volumetric flask sizes comply with requirements for Type 1, Class A "Unserialized flasks". They are supplied with a standard taper penny head glass stopper. Calibrated "to contain" at 20°C. Reference: ASTM E288 and Federal Specifications NNN-F-289. NOTE: LG-8110-100 and LG-8110-134 are not volumetric shaped. 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.