This is a set of the 1/4" ball bearings that fit the older model loose ball bearing steering head / triple tree. Used on other brands as well I am sending you 21 balls, although most bikes use 20 per race. or 40 for a typical bike.  A few spares could come in handy!

If your doing both the top and bottom look at my Ebay sale for 41 of them  and save a little money

Used on many brands, BSA, Norton Triumph on loose 1/4" ball bearing steering head, neck, Triple tree bearings