A range of solid rubber stoppers / bungs ideal for closing test tubes and flasks.
The numbers in each description denote the base/upper stopper diameter in mm - e.g. 3/4.5mm.
The Shore hardness of these bungs is A45-A55.
These stoppers are suitable for use in contact with food; "The Natural Rubber Moulding grade 45-55, uses ingredients as specified in FDA regulation 21 CFR 177.2600 to manufacture rubber articles intended for repeated use and in contact with food."