Key Specifications
Standard: Manufactured to BS 2775 (1978/1992), which specifies dimensions and quality for laboratory rubber bungs.
Material: Typically made from flexible natural rubber, suitable for vacuum and ventilated glassware.
Hole Dimensions:
Bottom Diameter 5mm to 8mm: Typically feature a 3mm hole.
Bottom Diameter 9mm and above: Typically feature a 5mm hole.
Sizing: Each stopper has a moulded-in number on its surface that corresponds to its bottom diameter in millimeters (e.g., a stopper marked "15" has a 15mm bottom diameter).
