Higley has some weight options too. On a 4-stroke (like Dave's pic shows) you have two nuts - the spinner hub and the thin safety nut behind it. You can get a heavy hub or a light hub and you can get a heavy nut or a light nut. Their combined weight plus the weight of the prop can be used to balance a plane. Of course, for a 2-stroke you do not need the safety nut. For example, an APC prop may weight 1.9 oz. for a specific size while a Zinger wood prop of the same size may weigh .9 oz.

Just sayin ...