Nauticam N120 Extension Ring 10 with screwsThe Nauticam Extension Ring 10 with screws is part of the N120 Port System and can be used to add 10mm effective length to an N120 Port setup. This extension ring supports the use of ports extension rings that have removable bayonet mounts. See Port Chart for more details on choosing the correct extension and port. Technical Specifications Depth Rating 150m Port System N120 Weight Port Opening Diameter 98mm Port Diameter Body Material Anodized