Make sure this fits by entering your model number. MATTE BLACK Gunmetal finish - this is a black finish with hints of stainless steel, very similar in color to black stainless steel appliances. | UNDERMOUNT Installation. Sink is constructed of thick 16 GAUGE T-304 Grade Stainless Steel that will NEVER RUST or tarnish. The COLORED FINISH is applied as an outer layer using an innovative nano-PVD technique that makes it INCREDIBLY TOUGH and RESISTANT TO WEARING or PEELING.