In order to archive real-time precision turntable speed measurement, a state-of-art gyroscope sensor is embedded in this product. By using this product, you can measure and monitoring turntable speed while playing records. The monitoring of turntable speed and precision speed adjustment become very easy and straightforward. The built-in multicolor LED start to flash whenever the deviation rate of turntable speed below 0.3%. The flash of LED is an indication of turntable speed in acceptable range. The scale of speed reading is 0.01 rpm. The accuracy of measurement is +/-0.01 rpm.