#1 Silicone Rubber Stopper with Optional Grab Ring | Food-Grade Bung for Laboratory Glassware, Test Tubes & Small Specialty Bottles

#1 Silicone Bung / Stopper

Our #1 Silicone Stoppers provide a precision-molded, airtight seal for openings ranging from 13.5mm (bottom) to 18.1mm (top). Crafted in the USA from 100% food-grade silicone, these stoppers are non-porous and odorless, ensuring that they will not absorb flavors or leach chemicals into your samples or spirits. The Grab Ring option is specifically designed to allow for effortless removal from narrow-necked glassware without risking damage to the vessel.

Multiple Tooling Options: Available as a Solid stopper for airtight storage, Bored (with a 15/64" hole) for small-batch airlocks, or with an integrated Grab Ring for easy manual removal.

Superior Chemical Resilience: Resists cracking, chafing, and mold, outperforming standard rubber stoppers in longevity and hygiene.

Extreme Temperature Tolerance: Stable and flexible from -100°F to 400°F, making these stoppers suitable for both freezing and high-heat sterilization or distillation.

BPA-Free & Safe: Certified compliant with FDA Industry Standard 21CFR177.2600, making them safe for food, beverage, and medical applications.

Grab 

Solid / Hole

Hole Diameter = 15/64" (5.95 mm)