N85 to N120 41.5mm Port Adapter ~with Zoom/Focus KnobAn adapter to convert from an N85 port opening to N120 port opening for use with the NA EOSM5 with Canon EF EOS M adaptor and Canon EF mount lenses. The extension also has an integrated zoom focus 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