Reply to BrunoAndre88:
For the GO Pro 10, you need the underwater housing of the Go Pro 9, as I bought it myself. I have not yet been able to discover an original Go Pro 10 housing on the market, so I assume that only the underwater housing of the Go Pro 9 is available for the time being. Max. Depth 60 metres! Attention: housings from non-Go Pro suppliers or non-original housings are usually only suitable for depths of up to 40 metres. I assume that the housing of the 9 is not compatible with the 8, so be careful...also be careful when buying the red filters, as these are also different.

I changed from the Hero 7 to the Hero 10 myself. To my disappointment (too little research), the batteries no longer fit, as the new ones are larger. Since the battery capacity is rather low due to the greater consumption of the Hero 10, it is almost mandatory to buy an additional battery.
The case of the Hero 7 no longer fits, as the Hero 10 is larger. However, you no longer need it because the Hero 10, like its predecessor, already has the holder connection for the hand grip, for example, integrated.
So if you switch from the Hero 7 to the Hero 10, you have to buy the accessories again. Too bad, but that's just normal in the electronics world.