Foam Stopper 35-45mm
Breathable foam stoppers will withstand boiling or autoclaving temperatures, making them ideal for use in preparing a yeast starter. The honeycomb structure of the foam stoppers will act is a filter for any airborne bacteria or wild yeast that might enter the flask. That important because a lot of air is sucked into the flask while it is cooling. You can also leave the stoppers on the flask instead of a fermentation lock. Some people use foam stoppers to replace fermentation locks in their carboys, too.
The small foam stoppers are 35-45mm wide and fit our 500 or 1000 ml borosilicate glass flasks, or a glass carboy.
No additional information.
Its a foam stopper. It fit the erlenmeyer. End of story.
Actual diameter is 45mm or 1 3/4". My Kimax 5000ml flask has a 42mm opening and this fits perfect. It can of course be squished as small as you want it.
I freakin love em. I stuff em in my ears so I don't have to hear the wife blabbering. And they provide the appropriate air exchange for my algae cultures.
Works perfectly. Allows air in to oxygenate started and keeps dust out.
As cheap as these things are (NB please don't up the price) I buy a few with each order I make. They're easily sanitized, and actually could take a lot of use before being pitched. Follow their sizing instructions to make sure you're buying the right size for your e flasks.