For your DJI Mini 4K drone (which is probably a DJI Mini 3 Pro, as there is no official "Mini 4K"), there are several accessories that are compatible:

- Battery: The DJI Mini 3 Pro uses specific batteries that are not compatible with other models such as the Mini 2 SE or Mini 2. A suitable charger is the Two-Way Charging Hub, which can charge three batteries simultaneously.
- Propellers: The propellers for the DJI Mini 3 Pro are specific to this model and should not be interchanged with other models.
- Bag: A waterproof hard case is useful for transporting the drone safely. DJI does not offer its own hard case, but there are many third-party supplier options.

Make sure you buy accessories specifically designed for the DJI Mini 3 Pro to avoid compatibility issues.