Sealux PS Macro Port dimensions

Hi,
hope here are some Sealux user, who can help me.

I have a Nikon D500 in a Hugyfot housing, and plan to use a Sealux PS port with a Adapter ring ( i have one )
Ps port, simply because of light possibilities and weight.
But i Need the lenght of the port inside to figure out which one will be the best solution.

Sealux has no dimensions on their page, and the Adapter will add some lenght,
so i hope some users here can help me.

Would Need the lenght from the front glas element inside to the end of the port.
Have some normal Sealux macro ports, but they are too long, so i then can find out which one will fit.

Thanks a lot,
Wolfgang