These Professional Series Boards provide precision unmatched by any previous tournament board. Measurements are accurate within .003 of a inch. This accuracy is achieved through a revolutionary patented system; a system of exact, machined 90 degree angles – providing steps to enhance measurement and provide the most precise measurement on the fish measuring board. The black anodized rule allows for quick visual measurement. Constructed of aluminum the Golden Rule Professional Series board is 1/4″ thick x 2 1/4″ wide making them stronger and more accurate than the Original Golden Rule.