Rubber Stoppers (Rubber Bungs) – 2 Hole, 18mm Bottom (Pack of 10)

These 2‑hole rubber stoppers, commonly known as rubber bungs, are versatile laboratory essentials designed to securely seal glassware while allowing two simultaneous connections. Supplied in a convenient pack of 10, they are ideal for routine use in school, college, and teaching laboratories.

Each stopper features a bottom diameter of 18mm, a top diameter of 21mm, and a length of 26mm, making them suitable for a wide range of flasks and reaction vessels. The two pre‑drilled holes allow easy insertion of tubing, thermometers, delivery tubes, or probes, supporting more advanced experimental setups.

Manufactured from durable, flexible rubber, these stoppers provide a secure, airtight seal while remaining easy to insert and remove, helping protect glassware during repeated classroom use.

Key Features

• 2‑hole rubber stoppers for laboratory applications
• Bottom diameter: 18mm
• Top diameter: 21mm
• Length: 26mm
• Supplied in a pack of 10
• Allows two tubing, probe, or thermometer connections
• Flexible rubber for a secure, reliable seal

Ideal for School Science Lessons & Practical Experiments

These 2‑hole rubber bungs are well suited to KS3, GCSE, and A‑Level science lessons, supporting practical experiments that require sealed apparatus with multiple connections.

• Connecting gas delivery and pressure‑release tubes
• Allowing use of a thermometer alongside tubing
• Supporting gas generation and collection experiments
• Constructing more complex chemistry reaction setups
• Enabling safe, repeatable student practical investigations

Reliable, reusable, and easy to handle, these 18mm 2‑hole rubber stoppers are an essential laboratory consumable that supports safe experimentation and effective science teaching in educational environments.