The product is a set of three 500ml flasks made by PYREX, a well-known brand in glassware. These flasks require  stoppers labeled as No. 7, providing a secure closure to prevent spills or contamination. Ideal for healthcare, lab, and dental settings, these clean USA-made flasks are precise in measurement and made of high-quality glass for reliable use in various experiments and procedures. With the PYREX brand reputation for durability and accuracy, these beakers are a valuable addition to any lab or medical facility.