Clear and accurate calibration allows you easy to read data. Helps tracking errors, especially on the inner grooves of the record. Ensures proper alignment for optimal sound. Works with any standard 1/2inch mounted from any . usage method: 1. Place the adjustment ruler on the turntable shaft of the record player.( points are red) 2. Move the gauge and the arm to drop the stylus at point A. Adjust the angle of the head so that the leading edge and the horizontal line on the scale are horizontal, which is more conducive to the mirror reflection. 3. Move the gauge and the arm to drop the stylus at point B. Check that the leading edge of the is square with the grid lines on the scale. 4. Repeat steps 2 & 3 until a square is formed at two points. Simply loosen the screw to move the , and after tightening, tighten the fixing screw. Colour:Transparent Material:Acrylic Package Contents: 1 x Adjustment Ruler Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.