These 500mL PYREX(r) distilling flasks are used for the distillation of bituminous materials suitable for road treatment. Also used in the Standard Method of Test of the Distillation of Creosote Oil, American Wood Preservers Association, method 11e, Barrett method C 9, American Association of State Highway Officials, methods T 52 and T 62. Flasks take a No. 5 rubber stopper.