nofxpunx1980

I am a homebrewer of beer/mead. A buddy of mine picked up a nice Erlenmeyer flask for me. I would like to find some ST ground-glass adapters for it so i can adapt it to some of my other 24/40ST labglass. It appears that the flask has a thick, beaded top, end on it. 2" ID and 2.75" OD. It does not appear to be a ball-joint end fitting. Not quite sure on the nomenclature. what do you call this type of flask joint?