5000 ml Erlenmeyer Flask5000 ml Borosilicate glass flask is perfect for making very large starters for high gravity beers and lagers. This flask will take a medium universal stopper or a 46 60mm foam stopper. Do not heat on stove top electric burners use gas burners only. California Proposition 65 Proposition 65 Warning: This product can expose you to chemicals that are known to the State of California to cause cancer and birth defects or other reproductive harm.