The Shinwa digital protractor or digital angle finder uses a stainless steel folding rule design with 280mm legs.
To zero the device align the legs and press the zero/on switch, if measuring for a chopsaw you may wish to start from 90. Press the legs into position against the surfaces to be measured, the angle is displayed on the readout and can be stored by pressing the hold button. The pivot between the two legs can be tightened or loosened by twisting the black ABS knob.
The digital scale will measure upwards from 0° to 360° regardless whether the blades are moved clockwise or anticlockwise, so if you need external or reverse angles just go the long way round.
One scale is laid out as a continuous 600mm rule starting from the left hand end, the other begins in both directions from the centre of the internal angle when the legs are set to 90 (like a Japanese carpenter's square).
Display resolution 0.1 degree
Display accuracy 0.3 degree