I bought this to use with the basin mate, which needs a quality backnut to tighten it up - not the plastic one that comes with the waste. Very nice product, well finished and delivered very quickly.
This brass basin waste back nut is a vast improvement on the inadequate plastic versions normally used these days. I needed a replacement for a plastic back nut that had fractured (as usual). I ordered two brass nuts with washers. They arrived 20 hours later- thank you Stevenson for the lightning fast service and good communications. (Stevenson's website explanation clears up the confusion between 11/4 inch BSP thread and the actual measurement of these nuts. This was most helpful)