VWR® Burets are made from Borosilicate 3.3 glass, ASTM 438 Type 1, Class A standard

• Supplied with a chemically-resistant, self-lubricating PTFE stopcock plug
• Used primarily for titration, to deliver one reactant until the precise endpoint is reached
• Calibration and tolerances per ASTM E287, ASTM E542, ASTM E694, and ISO 385 Standards

The graduations are typically calibrated "to deliver" (marked "TD" or "EX") at 20 to 27 °C and indicated correspondingly on a label. Serialized, individually certified products.

These Burets are calibrated to deliver a precise volume at a particular temperature.