Schluter Rectangular Shelf for Prefabricated Kerdi Board SN/-SNLT Niches - 4mm Thick, Curve Design, Stainless Steel Material, Brushed Stainless Steel Finish - SNS1D6EB. The Schluter Systems Shelf-N Curve in Brushed Stainless Steel (SNS1D6EB) is a high-quality, stylish shelf designed to enhance your bathroom or shower space.