These Pyrex® burets are suitable for use in school and institutional laboratories not requiring Class A accuracy. Supplied with a PS PTFE stopcock plug to reduce freezing and eliminate lubricant contamination. The microfinish of the barrel provides a precision fit. The tips are carefully drawn for accuracy to insure proper drainage rate. Each buret is supplied with a dust cover and has a permanently colored scale. All sizes furnished with a 2mm bore stopcock plug. This buret has durable colored markings. For replacement plug assemblies, see Cat.No. 1-7681-2.