I have a brand new 6inch Ikelite dome port for a lens 5-6" (Part number 5503.85).
I have never used it as it does not work with my one and only lens, a 10-20mm sigma!
I am looking to sell the port and replace it with the correct one.
Attached are two images of the port.
Email me at justinblake82 at gmail.com if you are interested
I am looking for $180 for the unused port.