One Pound of Two-Hole Rubber Stoppers in Various Sizes.

• Pliable
• Autoclavable
• Sizes: #2 to #8

Black stoppers are made of solid natural rubber that stays pliable over a long period of time. Ideal for use with non-aggressive or concentrated solutions. Stoppers feature a low sulfur content, and will withstand temperatures from –25 to 70 °C (–13 to 158 °F).