The Type F50, in size 4, has only one ear while Type F50, in sizes 5 through 9, has two ears. The distance between the ears on sizes 5 through 9 is 12.70mm or 1/2 inch.
The Type F50, in size 4, has only one ear while Type F50, in sizes 5 through 9, has two ears. The distance between the ears on sizes 5 through 9 is 12.70mm or 1/2 inch.