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 1 mL and 2 mL sizes are test tube shaped. Sizes 3L through 6L have pennyhead standard taper stoppers.
For stopper only, see Cat. Nos. 7650 and 7661.