This 2800mL wide mouth PYREX Fernbach-style culture flask is designed for culturing organisms requiring a large surface area to volume ratio. It can also be used in serum production. Triple baffled on the bottom outside edges to achieve maximal oxygen transfer to culture medium. Beaded neck rim is approximately 60mm I.D. and accepts cotton plugs or No. 13 rubber stoppers. This flask has a large marking spot. Note: Do not use this flask on a heat source smaller than the base of the flask. Uneven heating of the flask could cause breakage.