These larger volume PYREX® burets are suitable for use in school and institutional laboratories not requiring the accuracy of our Class A models. Supplied with a 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.