Rubber Stoppers (Rubber Bungs) – 2 Hole, 25mm Bottom (Pack of 10)

These 2‑hole rubber stoppers, commonly referred to as rubber bungs, are high‑quality laboratory components designed to securely seal glassware while allowing two simultaneous connections. Supplied in a convenient pack of 10, they are well suited to routine use in school, college, and teaching laboratories.

Each stopper features a 25mm bottom diameter, 28mm top diameter, and a 28mm length, making them suitable for a range of medium‑sized flasks and reaction vessels. The two pre‑drilled holes allow the safe insertion of tubing, thermometers, or probes, supporting more advanced experimental assemblies.

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

Key Features

• 2‑hole rubber stoppers for laboratory applications
• Bottom diameter: 25mm
• Top diameter: 28mm
• Length: 28mm
• Supplied in a pack of 10
• Allows two tubing, probe, or thermometer connections
• Flexible rubber construction for a secure, reliable seal

Ideal for School Science Lessons & Practical Experiments

These 25mm 2‑hole rubber bungs are ideal for use in KS3, GCSE, and A‑Level science lessons, enabling students to construct and investigate more complex experimental setups safely and effectively.

• Connecting gas delivery and outlet tubing
• Allowing the use of a thermometer alongside tubing
• Supporting gas generation and collection experiments
• Building more advanced chemistry reaction apparatus
• Enabling safe, repeatable student practical investigations

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