A set of 3 Corning PYREX low form glass beakers (#1000-Series) with a Magnetic Stir Bar. 3 piece Beaker Set consists of one each of 50ml, 100ml, and 250ml beakers. Magnetic Stir Bar, PTEF, Pivot Ring, 25x7mm. Griffin Low Form Beakers are made of 3.3 borosilicate glass. Double Scale, Heavy-Duty, beaded rim and a spout designed to have excellent pouring characteristics., white marking spot, and uniform wall thickness throughout. 3.3 borosilicate is the highest level of inert glass available. Designed from ASTM Specification E960, Type I requirements. If you have any questions or concerns, please contact us. We are happy to make it right!