The port has a M67 screw mount on the front.
[Required component] NX Compact Macro Port Base
[Depth rating] 100m / 330ft
[Dimensions (DIAxD)] 103x54mm / 4.1x2.2inch
[Weight] Approx. 210g / 7.4oz
[Construction] Corrosion-resistant alminum alloy (anodized) + Tempered glass (multi-coated)
[Distance] Between the mount and the inner glass surface: 35mm / 1.4 inches