Protractor Alignment Tool Turntable Phonograph Record Cartridge Stylus Features: Helps eliminate tracking errors, especially on the inner grooves of the record. Clear and accurate calibration allows you easy to read data. Features mirror surface with printed directions on back. Ensures proper cartridge alignment for optimal sound. " How to Use: 1. Place the calibration ruler on the turntable shaft of the record player. 2. Move the gauge and the arm to drop the stylus at point A. 3. Adjust the angle of the head so that the leading edge and the horizontal line on the scale are kept horizontal, which is more conducive to the mirror reflection. 4. Move the gauge and the arm to drop the stylus at point B. 5. Check that the leading edge of the cartridge is square with the grid lines on the scale." Specifications: Material: Acrylic Pacakge include: 1* Calibration Ruler 1* Cleaning Cloth