Science folks and DIYers, these #00 black rubber stoppers are exactly what you need for sealing test tubes, pipes, and various containers! The tapered shape is super practical - 11mm at the small end, 15mm at the big end, and 20mm tall - making them perfect for creating airtight seals in different sized openings. Made from quality rubber that's highly elastic with excellent insulation and sealing properties. They handle high temperatures well and resist acids and alkalis without dissolving or swelling, which is crucial for lab work. The moderate hardness means they're firm enough to stay in place but flexible enough for easy insertion and removal. Each package contains 12 stoppers, giving you plenty for multiple projects or replacements. Perfect for test tubes, fish tank holes, piping applications, or any situation where you need reliable sealing. Important note: these are for industrial or lab use only, not for food or bath applications. The black color makes them easy to spot, and the solid construction means they won't crack or degrade quickly. Whether you're a student, teacher, researcher, or hobbyist, having a supply of these reliable stoppers on hand makes experiments and projects so much smoother. They're one of those simple but essential supplies that you'll be glad to have when you need them.
Free 30-day returns 
Free 30-day returns
