This John Boos 20 x 15 x 2 1/4 inch RA cutting board in walnut is thicker than the John Boos R cutting boards. This size of board weighs 17.3 pounds and, like all John Boos products, has a long lasting and sanitary cutting surface. This cutting board from John Boos is especially are durable because it's crafted in the USA from from walnut, an extremely durable wood. This wood is one of the hardest types of wood available. A hard wood is important for a cutting board, because the hardness helps to minimize warping. This board will outlast softer, cheaper boards.