N2 Series 4-Leg Combo Unit, Bookrack features a plastic seat with a welded-on steel rod bookrack. Spacious High-Pressure Laminate Top 18"W x 24"D x 5/8" thickness. 18" Seat Height, Steel Frame, and Nylon-Base Swivel Glides. Wood Composite Core With High-Pressure Laminate Work SurfaceWork surfaces with a wood composite core have become the standard of choice because of the overall value.