My mare is 15.2h and wears a 4.5 in a bit. I started her in a hackamore when she was about 6. She wears the hackamore most of the time, and when we absolutely need to use a bit she wears a happy mouth mullen. Of course the smallest this comes in is 5", but because there are no joints it doesn’t seem to irritate her as much. There are more of an assortment of smaller bits these days. I don’t show too much any more so just stick with what we have.
