Features: 100% brand new and high quality. How to Use: loosen the screw, pull the V-shaped block along the base of guide wheel rotation, looking for goal angle. use of principle of reading the cursor, the main scale on the index of 1 , cursor index of 10 '. The "0" line on cursor is aligned with the "0" line on the main scale to indicate that A measurement plane is parallel to reference plane and the B reference plane is perpendicular to the reference plane. Technical indicators:(1) When measuring surface A is parallel to base surface and measuring surface B is perpendicular to the datum plane, "0" line of the cursor does not coincide with main scale "0" line is greater than 3 ', and curvature of both ends of the cursor is different from the main scale The degree of coincidence is not greater than 5 '; the other hand, tighten the screw so that the main scale 0 line and the cursor "0" line alignment, A measurement surface and the reference plane parallelism is not greater than 0.01mm, B measurement surface and the vertical plane Not more than 0.01mm. When cursor "0" line is on the right side of main scale "0" line, the degree is read out with the cursor "0" line, and the score is read out with scale of the right of cursor "0" line. A, B measuring surface counterclockwise turn the angle. When the cursor "0" line is left at the left of the main scale "0" line, the degree is read out with the cursor "0", and the score is read out with the left scale of the cursor "0" line. Read out the degree , points said A, B measuring the angle of the clockwise turn. in a fixed state, adjustable angle gauge indication error is not greater than 10. Package Includes: 1x Precision Adjustable Angle Gauge Specifications: Material: High Speed Steel Size: approx 102x30x49x30mm/4.02x1.18x1.93x1.18 inches Type: KP30 note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.