Bar ends size?

I am intrested in replacing the bar ends on my 1989 600r the bike was drop by the orinal owner, the next owner replaced all plastics and gas tank and gave it a custom paint job but sold to me before finishing replacing all scratched parts So the question is what size bar ends fit that bike i saw a set of 7/8 bar ends i am intrested in but do not know if that is the apropreite size Please help Thanks