10Pcs Erlenmeyer Flask Stopper Set, Silicone Plugs for Bottle Laboratory Test Tube Bungs Experiment Accessories Silicone Stoppers Suppliess - 16-18mm 5pcs, 27-31mm 3pcs, 38-41mm 2pcs

【Feature】- Made of high quality Borosilicate glass, Uniform wall thickness. Clear and accurate scales for you to measure liquid and approximate contents efficiently.  Reusable, environmental friendly, will not shatter easily, easy to clean, high temperature resistance. Silicone Stoppers are made of high-grade materials to ensure their safety and durability; small in size and light in weight, suitable shape allows for easy insertion and removal, convenient to store and use.

【Safe & Durable】- Offering superior heat, chemical and thermal shock resistance. These Borosilicate Glass Erlenmeyer Flasks have High chemical durability and low thermal expansion, which can withstand the temperature under 800 °C (~1500 °F). The Erlenmeyer Flask Stoppers are High elasticity, good insulation and sealing performance, high temperature resistance ,acid and alkali resistance, will not dissolve and swell in acidic liquids

【Application】- This narrow mouth conical borosilicate glass flask is ideal chemistry glassware for use in liquid measuring, laboratories, science experiment, schools, and for home, etc. These Silicone Stoppers are perfect for test tubes, flasks, and other bottles that require a secure seal. Can be used to block glass ports, pipe mouths, fish tank openings, etc.