Calibrated "to deliver" at 20°C, these borosilicate glass pipettes have a permanently colored white scale with the zero line at the top. Capacity of unit is just above the tapered delivery tip. Diameter is reduced at the top for ease in manipulation. Reference: ASTM E 1293 Style, Type 1, Class B NOTE: Do not pipette by mouth. Please use a mechanical device. 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.