Wood selection is something for you and your installer to discuss PRIOR to any of the installation process begins! There are several grades (qualities) of and types of wood planks one can chose from!
I elected to go with a Red Oak #2 grade of wood that was 3¼ inches wide and ¾ inches thick. A #2 grade is a lesser quality wood than a #1 which means it may have more imperfections/knot holes etcm. in the wood planks. 