We designed a dedicated protective case and a professional filter for O4 The protective case comes in four colors black yellow red and purple The O4 filter includes ND4 8 16 CPL Once the protective case is attached the camera size is 18mm perfectly compatible with DJI O4 AirUnitDescription DJI O4 AirUnit Weight 0 8gPackage Included ND Filters Sett ND4 8 16 Or 1 UV Filter 1 ND4 1 ND8 1 ND16