Are you talking about some kind of "conversion kit" that can be swapped onto a .45 frame? Way too many difference between a 9 and a .45 to make a one-size-fits-all conversion. At a minimum, you'd need slide, barrel, extractor, ejector and mag. The feed ramp in the frame might not be compatible, either. It's possible though, that with a complete 9mm top end and mags, you could get away with just changing ejectors to complete the conversion.