Fluepipe with roofmount. Fits on The Cointra Optima COB-5 Water Heater

Exactly what I needed!

I have ordered this quite expensive chimney to save me a hassle of trying to find one that would fit Cointra Optima COB-5.Unfortunately upon arrival I noticed that it's not going to fit, because it seems to be missing wider part at the bottom of the chimney that attaches to the gas heater. It looks different from the picture on Amazon.I thought that it's just a missing part so requested a replacement, however replacement looks exactly the same and does not fit.I've attached a picture so you can see what I mean and save yourself time and money.