I bought a new front door around 7 years ago, complete with brass door knocker and letterbox. It looked great! Unfortunately the door knocker began to tarnish and corrode, and looked decidedly grubby. It seems it was brass plated, and no amount of polishing would restore it. The letterbox, on the other hand looks as good as new! I did a little research online and discovered that 'PVD treated' brass will maintain its looks. There were a lot of different styles online; but I specifically wanted a slimline one and found exactly what I was looking for at 'Handles for Homes,' - and at a considerably better price than any of the other retailers. I am delighted with my purchase, and it has greatly improved the appearance of my door. Thank you all so much. PS - I bought a doorbell-push at the same time, but it hasn't been fitted yet. (All I need to buy now is a decent looking nameplate!)