SILGRANIT is made of quartz sand, the hardest element of natural granite making it long lasting and durable Easy-to-clean low maintenance material has a non-porous, smooth stone surface Effortlessly remove scuff marks from utensils and stains from food and drinks Undermount installation creates a seamless design that prevents dirt or grime from building up around the rim Optional accessories include grid (item #516363), foldable grid (item #238483), floating grid (item #233542) and decorative drain cover (item #517666) 80% Solid granite, Silgranit material features the touch and feel of natural stone Required outside cabinet is 33" Unsurpassed cleanability backed by industry leading 7 patents Bowl depths are 8" Limited lifetime warranty