Nauticam N85 to N120 55mm portAn adapter to convert from an N85 port opening to N120 port opening to allow for the use of N120 ports on N85 Port System housings. The extension also has an integrated zoom gear knob. See Port Chart for more details on choosing the correct extension and port. Technical Specifications Depth Rating 100m Port System N85 to N120 Conversion Weight Port Opening Diameter Port Diameter Body Material Anodized Aluminum Alloy Port Material Port Coating Port