Nauticam 4.33' dome partThis wide angle dome port is part of the N85 port system and features an acrylic element and anodized aluminum construction. Different size ports are available to support a wide variety of lenses and housing types. Port extensions or adapters may be necessary for some ports and housings. Technical Specifications Depth Rating 100m Port System N85 Weight Port Opening Diameter Port Diameter 4. 33" Body Material Anodized Aluminum Alloy Port Material