#7 universal solid stopper fits most 3-6.5 glass gallon carboys.
#9 universal solid stopper. Made for smaller barrels, such as 5 gallon American Oak (please check size.)
#10 universal solid stopper fits most 3-6 gallon PET carboys.
#11 universal solid stopper fits most larger barrels, such as 30-60 gallon French and American oak barrels. This bung will also work with converted Sanke kegs, where the spike has been removed.