The digital protractor is a revolutionary tool that provides an immediate digital reading of all angles in a 360° range. The unit utilizes a liquid-filled sensor combined with precision measurement circuitry to provide unparalleled accuracy and stability. The precision machined aluminum frame provides a rigid, lightweight, ultra-precise platform for extremely accurate measurements. The frame is grooved along the bottom surface to facilitate use with round objects such as pipes or shafts and incorporates threaded holes on the bottom for rigid attachment If desired. The front panel buttons can be used to capture desired readings or to designate an alternate reference surface from which subsequent angles are then measured. The unit can also be easily recalibrated in the field to factory accuracy using any available flat surface. Features full 360° range (90° x 4) East to read LCD display which flips over when unit is upside down maximum accuracy of ±0.1° and maximum resolution of 0.1° precision, machined aluminum frame unit can be recalibrated to factory accuracy in the field without special tools or fixtures automatic power down feature what's included: rigid plastic case full 360° range operate up to 500 hours on a single 9V battery.