The M300 RTK has an IP45 rating.

While this isn't a complete waterproofing, it does make the M300 RTK a robust aircraft which can handle a certain amount of rain and other challenging conditions.

In technical terms, its IP45 rating means that the drone is protected against solid objects greater than 1mm, such as screws and wires, and can withstand low-pressure jets of water from any angle.

Further reading: How waterproof is the M300 RTK?