This is a great record stabilizer for LP record player, which will efficiently keep the disc from shaking and reducing vibration with stabilizing rotational speed. Perfect for maintaining stability, and improving acoustic quality. For eliminating vibration, stabilizing rotational speed, and maintaining horizontal level of turntable. Realistic sound reproduction and lower noise provide you a pure and excellent enjoyment in music. Spindle hole is suitable for 7mm diameter of spindle, fit well with most of exist turntable. Built-in high precision bubble level, for testing weather the working surface is on the level and showing you the rotation speed of the vinyl disc. Velocimetry : Above LP Turntable tick is used to Velocimetry the, LP Turntable marked 60-33 / 60-45, such as turn 33 LP disc jukebox after turning up to see whether the tick marks 60-33 clearly visible, if the rotational speed uniform and clearly visible, proved normal speed for 33 revolutions per minute (or so), if more obscure or connected into a line, that speed is not correct. Note: Suitable for use in areas with a power frequency of 60HZ Function: 1.For record stabilizer. 2.To test the speed of record players. 3.To test the level of record player, cabinet and speaker. Speed measurement : , the record is pressed to the turntable of the record player, and the record player is turned on. After the record player rotates, it looks down under the fluorescent light to see if the tick mark is clearly visible. If the point on the tick mark line is evenly and clearly visible, it does not move left or right, then the rotate speed is accurate. If it is fuzzy or connected into a piece, and move left and right, then the speed is not normal. This test is for reference only. Speeds: 33,45,78 RPM Output Connectors: RCA Motor: Record Stabilizer colour:Bright black Material:Aluminum alloy size:76 x 34mm Package Contents: 1 x Weight clamp Only the above package content, other products are not included. Note: Light 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.