No. 6.5 Stopper - Drilled

Stopper

Plugs the hole just fine.

Better stopper

The 6.5 Drilled stopper that came with the purchase of a Big Mouth Bubbler EVO 5 Gallon Fermenter would push right through the lid opening. I reported the problem to NB and they stepped up to the plate and sent me a new stopper and a new lid. There is no way that the replacement stopper will push through the opening in the lid. Thank you NB!!

It's a stopper

Solid enough.