Big Mouth Bubbler EVO 6.5 Gallons Glass Carboy Fermentor With Universal Single Port Lid For Homebrew Beer The revolutionary Big Mouth Bubbler glass, re-engineered by world-class Polish master glassmakers Now features the new Big Mouth Bubbler Universal Single-Port Lid! Opening accepts a #6.5 Rubber Stopper or Small Universal Stopper Extra-thick glass eliminates oxygen permeation and keeps your brew safe Instantly measure volume with gallon graduation marks Easier transfer of clear beer with a taller, narrower body while ensuring less liquid is left behind The revolutionary Big Mouth Bubbler glass, re-engineered by world-class Polish master glassmakers<br> Now features the new Big Mouth Bubbler Universal Single-Port Lid! Opening accepts a #6.5 Rubber Stopper or Small Universal Stopper<br> Extra-thick glass eliminates oxygen permeation and keeps your brew safe<br> Instantly measure volume with gallon graduation marks<br> Easier transfer of clear beer with a taller, narrower body while ensuring less liquid is left behind