This is a custom manufactured port adapter for the ikelite Sl1 housing. It replaces the standard port on the housing and allows you to use any of the ikelite modular port items including the flat port or the 8" dome port. You just un-screw the original port from the housing and screw this one in. Then your housing is modular. I have used the adapter to test the ikelite 8" modular dome with the housing and was very pleased with the results.
The item is located in Cincinnati, Ohio USA and will ship anywhere as long as the buyer pays shipping, insurance and paypal fees.
I am asking $125 for the adapter.