XRAY - Model racing cars

Hi First post, I just got the hybrid xb2 and got the 16' xb4 last fall. I ran the stock xb4 horn for almost a year before it spun on the servo. So I intend to run the plastic horn on the xb2 till it skips/spins. I was wondering which hudy horn I should have in my bag as a back up. I'm seeing multiple hudy aluminum horns and was wondering which one fits best on the xb2. Thanks for all the help. I guess you could say I've been lurking here for awhile and I appreciate the help I've read on here.

On XB2 you can use these alu HUDY servo horns:

Thank You, I ended up getting the 3 hole yesterday. I guess I'll measure and cut if need be. Black paint pen over where I grinded.