EUC Pyrex 2800 mL Fernbach - Style Culture Flask with baffles. Product #4422-2XL. Designed for cultivating Organisms requiring a Large surface area to volume ratio. Triple baffled one the bottom outside eclaes to achieve Maximal oxygen. transfer to culture Medium. Beaded Neck rim is aproximately 60 mm I.D. and accepts cotton plug or no. 13 rubber stoppers.