Stoppers, Rubber Size 5, Solid. Pack of 1-Pound.

-Our high-quality rubber stoppers are soft, non-greasy and have a durometer of 45. They are sold in a one-pound pack. These stoppers are size 5 and are solid (no hole drilled). Size 5 stoppers have top diameter of 27mm, a height of 25mm, and a bottom diameter of 23mm. Approximately 29 size 5 stoppers are included per one-pound pack.Rubber stoppers are essential for creating airtight seals in laboratory experiments, making them ideal for chemistry, biology, and physical science classrooms.Sealing Glassware: Use rubber stoppers to securely close test tubes, flasks, and bottles, preventing spills, evaporation, or contamination during experiments.Gas Collection and Transfer: Stoppers with holes can hold glass tubing, allowing students to collect and transfer gases like oxygen or carbon dioxide during chemical reactions.Water Displacement Demonstrations: Use rubber stoppers to seal flasks or bottles in water displacement setups, helping students visualize gas production.Not safe for use with food products. PRODUCT WARNINGS WARNING: This product can expose you to chemicals including styrene and lead, which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information go to www.P65Warnings.ca.gov. Warning: Choking Hazard Our products are not toys. Use in a laboratory or educational setting only. Not for children 13 and under.