DigiPas DWL80E Pocket Size Digital Level, Electronic Angle Gauge, Protractor, Angle Finder, Bevel Gauge, 0.1&deg;, 4 inch DUAL FUNCTIONS - tilt/angle gauge to set and also check relative angles between two surfaces using Alternate Zero function EASY RE-CALIBRATION by user back to factory setting with no special fixture required (patented); RESOLUTION: 0.1 (0 & 90), 0.2 for 1 to 89, switchable display between degrees () or slope (%) STRONG MAGNETIC BASE: securely attach to fences, saw blade & base, and other metallic surfaces SMART TECHNOLOGY SENSOR; improve accuracy with precise displays in degrees, In/Ft, mm/M, % slope Measurement Range 0 ~ +/- 90 x 4 (360)