Rubber Stoppers / Rubber Bungs – 1 Hole, 25mm (Pack of 10) [1161]

These high‑quality 1‑Hole Rubber Stoppers are designed to provide a secure and airtight seal for a wide range of laboratory glassware. With a 25mm bottom diameter, 28mm top diameter, and a length of 28mm, they fit snugly into compatible test tubes, flasks, and other lab vessels used in school science experiments.

Each stopper includes a single pre‑drilled hole, making it ideal for inserting glass or plastic tubing for gas collection, delivery systems, and closed‑circuit experiments. Made from durable, chemical‑resistant rubber, these stoppers are designed for repeated use in busy school laboratories and practical demonstrations.

Supplied in convenient packs of 10, they are perfectly suited for class sets and group experimental work.

Key Features

• Durable rubber stopper with 1 pre‑drilled hole
• Bottom diameter: 25mm
• Top diameter: 28mm
• Length: 28mm
• Suitable for glass or plastic tubing insertion
• Provides a secure, airtight seal for laboratory glassware
• Resistant to common school laboratory chemicals
• Supplied in packs of 10

Ideal for School Science Lessons

These 1‑hole rubber bungs are ideal for KS3, GCSE, and A‑Level science investigations, enabling students to work safely and effectively when carrying out experiments involving controlled systems or gas flow.

• Creating gas delivery systems for chemical reactions
• Safely sealing flasks and test tubes during closed‑system experiments
• Supporting biology and chemistry investigations such as respiration, fermentation, or gas production
• Allowing controlled use of tubing for transfer or collection of gases
• Ensuring a secure, leak‑free setup in practical lessons

Durable, reliable, and designed for educational use, these rubber stoppers are an essential consumable for any school science laboratory.