Howshot 67mm threaded mount base is suitable for 100mm (3.9") to 104mm flat ports, including the housings which can attach Ikelite WD-4 Wide Angle Conversion Dome(*). It will protect the ports securely without rotating. Or easily attach macro lens with 67mm threaded, like INON UCL-330, UCL-165M67 or UN UNCU-01 Close-up Lenses to have macro photos.

* Notice: Ikelite WD-4 Wide Angle Conversion Dome can't be used with Deeproof 67mm threaded mount base at the same time.