These Class A Pyrex® microburets are designed for precise analytical methods in microchemistry. Precision bore tubing throughout the body assures accuracy between any two points. Funnel top facilitates addition of reagents by pouring, or by suction from below through a rubber-stoppered tube. Tips are tapered to assure smooth flow. 2mm bore Pyrex® ST stopcocks turn freely, yet give positive control. For replacement Pyrex® stopcocks, see No. 1-7680. For replacement retaining clips, see No. 1-7280. The capacity tolerance on these burets is established by ASTM E-1189 and is calibrated in accordance with ASTM E-542.