The DJI Mic Mini Transmitter can be used for content creation on both your iPhone and Sony A6400, but it may require additional components or setup methods for optimal performance.

### iPhone Compatibility
- You can connect the DJI Mic Mini Transmitter to your iPhone using Bluetooth, which is a quick and convenient method. However, this method uses Bluetooth compression, which can affect audio quality. For better audio quality, you can use the DJI receiver, which connects directly to your iPhone via a USB-C or Lightning adapter, providing uncompressed audio.

### Sony A6400 Compatibility
- To use the DJI Mic Mini Transmitter with your Sony A6400, you need to use the receiver that comes with the DJI Mic Mini kit. You will need to slot the receiver into the hot shoe on the top of your camera and connect it to the camera's microphone input using the provided audio cable. This setup allows for higher quality audio and more control over the audio settings.

### Additional Products Needed
- For both devices, the DJI Mic Mini Transmitter works best when used with the included receiver, especially if you are looking for high-quality, uncompressed audio.
- For iPhone, a USB-C or Lightning adapter may be necessary if your iPhone uses a different port type.
- For Sony A6400, the audio cable and the receiver are essential for proper connection and optimal audio quality.

In summary, while the DJI Mic Mini Transmitter can be used alone with Bluetooth for basic recordings, using the receiver and appropriate adapters will significantly enhance the audio quality and functionality for both your iPhone and Sony A6400.