Tune your turntable’s rotation speed to a precise level with Record Supply Co.’s Stroboscope Disc. Pattern is printed on a heavyweight acrylic disc and can be used with a strobelight (not included) to get the correct speed. Works with any turntable in which the speed is adjustable including an external motor or the use of a speedbox. Synchronizes at 33 1/3, 45, and 78 RPM. Flipside features cartridge alignment markings to properly align your cartridge and get the best sound from your system