Porter Cable part #39332
I've been trying to find this part for some time. Every where I turn says this part is no longer available.
I have found a good solution. McMaster-Carr sells a 1" smooth bore vacuum hose for $1.32 a foot. P/N 5641K21. Screw-on grey fitting for 1" ID, smooth bore duct hose for liquids, P/N 5641K61, $4.80, per unit. I am very happy with this solution. It has provided me with a "duct tape free" solution. There are many adapters that will adapt this 1" ID hose to the 2 1/4" ID port on my vacuum system.
I hope that this has helped.