Not sure exactly what you mean by that. The central tube down the middle of the cartridge filter is "open" with rubber gaskets at each end to fit snugly to the main bolt shaft, and has a bunch of holes/perforations in it for oil flow.
I just completed the IP oil change. Another PITA w115 job with old diesel fuel all over the garage floor that had built up in the pump. It kind of had a lacquer or turpentine smell to it.


PS - If anyone has W115 oil canisters for sale with a retrofitted drain on it, I would gladly buy it off you. I'll even send you my original one back.