Inclinometer, RISEPRO Digital Protractor Angle Finder Level Inclinometer Magnetic V-Groove 0~360 degree with Backlight 82413B USEFUL 3-IN-1 DEVICE WITH BACKLIGHT  This newest digital gadget features with protractor, angle finder and level in one measuring tool. Backlight helps you to work at dark condition. WIDE APPLICATIONS  Great tool for automotive, wood & mechanical industries, machinery, medical fields and etc V GROOVE BASE  The V Groove base with strong magnets enables strong attachment over a curve or cylindrical magnetic surfaces such as metal pipeline or shafts CONVERTS ANGLE TO OTHER UNITS : Conversions between : 4 x 90 m/m : 1000mm/m, % : 100%, in/ft : 12in/ft. No more guessing or fuzzy conversion! ABSOLUTE & RELATIVE MEASUREMENT  The regular absolute measurement mode can only measure the angle against horizontal plane. This tool also features with relative measurement mode for quickly measuring angle between two measured surfaces.