For opening the ampoule there is one option by a colourbreak ring. A coloured enamel ring is applied around the constriction with a disc.
A disc marks the glass surface all around the constriction of the ampoule. It is also possible to set a further colour ring above the scorering to see the kind of opening. The ampoule can be opened at each side.
A small incision (cut) is placed in the constriction of the ampoule with a disc. A small coloured dot marks the position of the breaking cut.