This accessory is designed to evaluate the speed of any turntable. The hand-held strobe unit generates a 100 Hz pulsed light source for use with the supplied 180-line stroboscopic disc. Designed as the perfect partner for the speed adjustable Rega Neo PSU. Simply place the supplied stroboscopic disc directly on the turntable mat. With the player running at 33 1/3 RPM hold the strobe LED directly above the lines to evaluate the speed of the turntable.