Manufactured in all standard sizes from 000 through 16 including half sizes. Available in almost any material and Shore 'A' durometer hardness.
Black Rubber: Especially formulated to answer most laboratory requirements, combines low cost with a soft resilient stopper for long life and good resistance to deformation. Hardness is 40 +/- 5 durometer. Low sulfur content and no known impurities.
Green Neoprene: Compounded to resist swell from most oils and other petroleum products. Colored light green for identification the organic pigment will not migrate or bleed. Hardness is 45 +/- 5 durometer.
White Rubber: Soft, pliable and resilient properties provide a safety feature when used with glass tubing. Formulated using a minimal number of ingredients to maintain purity. Will withstand repeated autoclaving and is nontoxic, odorless, and tasteless.
Silicone stoppers have been available in red and black for many years. However a non-pigmented stopper is required in many demanding applications such as plating and powder coating. East Bay Rubber's Translucent Silicone fills the bill and more. Now there is a stopper that can withstand up to 600 F. intermittently.

Click here to view the dimensions of our Laboratory Stoppers.