Mono Serra North Stone 12" x 24" porcelain tiles elegantly enhance the look of floors and walls with a trendy anthracite finish reminiscent of real stone. Each box contains 7 tiles, which can cover up to 14.42 sq. ft. It is recommended to install these non-ground tiles with a 5 to 7 mm grout joint. These grade-5 tiles feature a high-resistance design and include a warranty against any visual defect before installation.