Big Horn 14220 is a digital inclinometer that will read relative angles to an accuracy of +/- 0.2 Degree. Turn it on, place it on your saw table and press the Zero button once to establish relative zero. Then attach it to your blade by means of the rare earth magnets on its sides it will register the relative angle between the blade and the table on a large, easily read display. As a bonus, if you press the Zero button again, it will also measure absolute zero, which means that you can also utilize it as a portable pocket level. It has a durable metal case and is powered by a standard 9 volt battery, which is included.