1:What’s the difference between the O4 PRO and O3 versions?
The only difference is the camera mount – the O4\ O4 PRO version is optimized for the DJI O4 \ O4 Pro Air Unit.
2: Does the O4 version need to be paired with the Flywoo DJI O4 Camera Shell ?
Yes. In addition to the need to replace the Camera mount, you will also need to use the Flywoo O4 Camera shell