Hey
No, the housings have different dimensions (on purpose, money-making?) and new filters have to be used. The housing of the 4 doesn't work for the 5/6 either... at least these two have the same housings :-) By the way, batteries from the 4 don't work either :-S
There are some from Gopro itself and some from Polarpro:
https://www.digitec.ch/de...