As I said before, I have the metal pipe in the shower that I need to attach the drain to. I bought the ABS adjustable drain for tile showers, and I will be building the shower pan. I was told to use a rubber coupling to attach the metal pipe to the pvc drain. Is this correct? It doesn't seem like it will be completely waterproof, and will this material disintigrate after time? This just does not seem right. Do I have the right drain?

Nevermind, I got my answer from a plumbing supply store. I'll never listen to Home Depot or Lowe's again, they both steered me in the wrong direction. Thanks to you guys, I didn't listen!