FOWLER DIGI-PRO ELECTRONIC PROTRACTOR THE DIGI-PRO 12""/300MM ELECTRONIC PROTRACTOR INCLUDES EMBEDDED MAGNETS FOR UNIQUE MEASUREMENT AREAS. USE THE DIGI-PRO TO MAKE FAST AND ACCURATE ANGULARD MEASUREMENTS. ON/OFF ZERO HOLD AND REVERSE FEATURE TO INVERT THE DISPLAY FOR EASIER READING IN CERTAIN SITUATIONS. EMBEDDED 25 LB. PULL MAGNETS. FULL 360 degrees MEASURING RANGE. ACCURACY plus or minus.2 degrees REPEATABILITY plus or minus.05 degrees RESOLUTION .05 degrees INVERTIBLE DISPLAY FEATURE VOLTAGE STANDARD 3V LITHIUM BATTERY