These PYREX® Brand 5642 Class A volumetric flasks feature machine-blown bodies and heavy-beaded, heavy-tubing necks to provide excellent durability. Volumetric flasks include a linear high-density polyethylene stopper that conforms to stopper dimensions. The graduation line is sharp and permanent. Large white block letters make the inscriptions easy to read. The 2-mL flask is test tube shaped.

When taper sizes are given, the first number is the stopper diameter (mm) across the top; the second number is the stopper length (mm). If only one number is given, it indicates the stopper diameter (mm) across the top.