This is a small digital protractor providing accurate, easy-to-read results. Permanently calibrated, it will measure plus or minus 180° with a resolution of 0.1°. Measuring just 55 x 60 x 32mm, it is small and light enough to carry around in your pocket. The flip-up LCD screen makes it convenient to read. Magnets in the base hold the gauge firmly in place on saw bench tables, planer beds and saw blades. A groove in the base allows you to use the gauge on pipes etc. The five minute auto shut-off feature ensures long battery life. This must-have tool enables you to set up or check circular saws, mitre saws and many other machines with complete accuracy. It requires two AAA batteries (not included).