United Scientific™ RSTPK3 Premium Laboratory Black Rubber Stoppers, 1 Hole | Good to Seal Bottles, Tubes and Many Other Containers | #00 to #7 Assorted Sizes | 1LB of Stoppers | Pack of 54 Stoppers.

One-pound bag of black rubber stoppers with one hole, sizes 00 to 7. Made of natural rubber that stays pliable over a long period of time. Ideal for use with non-aggressive or concentrated solutions. Low sulfur content. Will withstand temperatures from –25°C to 70°C (–13°F to 158°F). Autoclavable.

• Tapered Design - Smooth and tapered sides make these stoppers easy to plug and pull. All United Scientific rubber stoppers are reusable, and promote a sustainable laboratory or classroom environment.
• Natural Rubber - Made from premium natural rubber, not easy to deform, elastic and great for sealing. Manufactured according to laboratory standards.
• Extensive Use - Rubber stopper Ideal for laboratory and industrial use, can be used to seal test tubes, flasks, etc. Available in a wide range of sizes.
• Low sulfur content. Withstand temperatures from –25 to 70°C (–13 to 158°F). They do contain latex.
• Size: #00 to #7 Assorted sizes, 1LB stoppers.