Plenty long and wide to fit on handlehd vodal mics like a
'Audio Technica AE6100'
or smaller microphones shaped like a Shure SM58.
There is a some slack or wiggle room for the mic inside the pouch, but doubtfully a problem unless someone is going to shake the mic forcefully and rigorously sideways.
Attachment is done by tightening a “pull string”, i.e. a tie cord and a friction clamp on the cord., and works fine.