18/10 Stainless steel brushed finish cylindrical sink. Brushed Finish sinks are constructed from the same quality 18/10 stainless steel as the mirror finished sinks, but offer a durable finish to last the lifetime of your boat. Brushed finished sinks are recommended over the Mirror finished sinks for exterior installation due to the reflective nature of the mirror finished sinks. 2-3/16" Drain opening, Profile A.