The classical stoppered reagent bottles are moulded from DURAN® borosilicate 3.3 Type 1 glass, and are suitable for the storage of liquid and solid chemicals and reagents. The bottles feature a narrow conical ground joint neck and comply with ISO 4796-2. The narrow neck is suitable for liquids and the angle of the shoulders ensures that the contents can be smoothly poured. The glass stopper provides an excellent seal that protects the contents from evaporation, oxidation, and contamination. The bottles have a Retrace Code for manufacturing lot traceability and a marking field in permanent white enamel.