Pro-Ject Strobe IT is a strobe test record that allows you to correctly set the speed of your turntable (where fine tuning the speed is possible).
Simply run the record on your turntable and change the speed while watching the rings and wait for them to change from delayed to constant to set speed. Use the inner rings to set speed at 45rpm and outer rings to set speed at 33rpm. The useful and innovative combination of a stroboscope - AKA, a speed-checker for your turntable - and a cartridge alignment tool. An essential accessory for any turntable enthusiast.