This round kitchen copper sink has a standard 3.75"" diameter hole at the bottom center, it fits the 3.5"" diameter drainage size. The rim around it is about 1.5"", so the internal dimension is 15"" diameter x8"" depth. The bottom diameter is about 10.5"". The copper sheet is 18 gauge (0.04"" thickness). The finish is in weathered copper, which is antique-looking.IMPORTANT NOTE: The patina can be damaged faster if abrasive substances are used to clean it, because of this, we recommend rinse it with water and soap only!