Bloody lots of them here! Simple and cheap ones, good quality ones, and one that worked with a CO2 bulb (very scarey if the cork was reluctant to come out, and the fear that the bottle might explode)! Very conservatively I would say at least eighteen. I currently, for some reason, have three cheap ones, but what stands out is the fact that I still have my dead simple one, from 1970, which will still do the job when all else fails....