As I said sorry for the rant. The LHS was wrong in your case but there are some Hobbico, Tower, Hitec, and Futab servos that do happen to use the same horn. It is all very confusing and difficult, even for us smart people, again sorry.

Oh, to help... I have a set of calipers that I use to measure the inside diameter of the servo horns splines. Sometimes if you do not know if the horn is the correct one that may help especially since there are some that are visibly identical such as the white JR and Hitec ones.