Warertight optical-glass dome ports are finely ground to the highest standard. See Hollywood Divers 7days per week for Different size ports to support a wide variety of lenses and housing types. Port extensions or adapters may be necessary for some ports and housings. This optical-glass wide-angle dome port has a glass diameter of 180mm and is part of the N100 opening port system!!! This dome can be used with many of the Olympus, Panasonic, Fuji or Sony Emount Camera housings such as the A6500 A6700