Nantucket Sinks T-FCFS-20 - 20" is a Fireclay Farmhouse Kitchen Sink includes bottom grid and drain. Features an elegant 1and4" taper from top to bottom. It is made from dense fireclay with a porcelain enamel glaze that provides long lasting durability. There are many benefits to fireclay. Its glazed surface inhibits bacterial growth more than stainless steel. It is eco-friendly requiring less cleansers, Apron Height: 10"Exterior Dimensions: 20" x 17.375"Interior Dimensions: 18.5" x 16.25"Due to firing process, shrinking will occur and named dimensions are nominal only.Apron Height is 10"Due to bottom thickness of sink, an extended flangeandextension ferrule is required for the drainDrain opening is standard 3.5" kitchen drain.Mount Type: UndermountSink Type: ApronBowl Type: Single BowlNumber Of Bowls: 1Sink Shape: RectangleInterior DampSinks OnlyDrain Opening: 3.5Sinks OnlyDrain Included'': YesSinks OnlyDrain Required: 3.5" StandardCustom cabinet base required.