This specification covers requirements for glass burets of precision and general-purpose grades suitable for laboratory use. Burets are classified as: class A - precision grade buret, and class B - general purpose burets. Burets shall be calibrated to deliver the intended volume at 20°C. No after-drainage period is allowed. Self-zeroing burets shall have an ungraduated, tapered, interior extension that terminates with an overflow orifice. Burets may be equipped with a filling tube. All burets shall have permanently attached stopcocks. The stopcock's handle shall be located to the right. Stopcock plugs shall be provided with a retaining device.