CORNING 5640-100
The strength of these flasks has been increased appreciably through machine-blown bodies to which are sealed heavy-tubing necks tooled for standard taper glass stoppers. The graduation line is sharp and permanent; large white block letters make the inscription easy to read. The 1mL and 2mL sizes are test tube shaped. Sizes 3L through 6L have pennyhead standard taper stoppers.