Burette Grade A with Stopcock is a graduated glass tube with a tap at one end, for delivering known volumes of a liquid, especially in titrations.Burettes are manufactured from precision bore Boro 3.3 tubing for accuracy;Schellbach tubes are offered for accurate reading of meniscus;In-House manufactured Burettes DO NOT have Schellbach Stripe;Calibrated on computer controlled machines;Quality Control rechecks the burettes for accuracy;