This would fit on a haro…right?

Nope

Have you looked at your sprocket? I had that problem on an old bike. The sprocket hole got elongated to an oval shape. Buying a new sprocket would be cheaper and a better choice, regardless of the slim chance those would work.

Technically yes it would fit/work………..
However……….all the die hard BMXr’S would bust your b@lls all night for putting a MTB crank and on a dope #HARO 🤔😂😜