Rubber Stoppers (Rubber Bungs) – 1 Hole, 33mm Bottom (Pack of 10)

These 1‑hole rubber stoppers, also known as rubber bungs, are essential laboratory components designed to securely seal glassware while allowing tubing, thermometers, or probes to pass safely through. Supplied in a convenient pack of 10, they are ideal for routine use in school, college, and teaching laboratories.

Each stopper features a 33mm bottom diameter, 38mm top diameter, and a 38mm length, providing a snug, reliable fit for a wide range of flasks and test vessels. The single pre‑drilled hole allows easy insertion of glass or rubber tubing, making these bungs highly versatile for chemistry, biology, and physics experiments.

Manufactured from durable rubber, these stoppers offer excellent flexibility and grip, helping to create an effective seal while remaining easy to insert and remove without damaging glassware.

Key Features

• 1‑hole rubber stoppers for laboratory use
• Bottom diameter: 33mm
• Top diameter: 38mm
• Length: 38mm
• Supplied in a pack of 10
• Suitable for use with tubing, thermometers, and probes
• Flexible rubber construction for a secure, airtight fit

Ideal for School Science Lessons & Practical Experiments

These rubber bungs with a single hole are widely used in KS3, GCSE, and A‑Level science lessons, supporting a variety of practical investigations that require sealed apparatus with controlled access points.

• Sealing flasks and test vessels during chemical reactions
• Allowing safe connection of rubber tubing for gas collection
• Inserting thermometers to measure reaction temperatures
• Constructing apparatus for gas generation experiments
• Supporting safe, repeatable student practical work

Reliable, reusable, and easy to use, these 1‑hole rubber stoppers are a laboratory essential that help teachers and technicians prepare safe, effective experiments while reinforcing good scientific practice in the classroom.