These 1000mL PYREXPLUS coated heavy wall flasks have protective PVC coating for longer product life and safety. Protective coating helps prevent glass from shattering, reduces spills and is autoclavable (121°C) and resistant to thermal shock. For convenience, the flasks are graduated to show approximate capacity. The neck finish affords an excellent fit for rubber stoppers and uses a No. 6 rubber stopper. The 10mm tubulation is not coated to allow easy connection of standard size tubing.