Pro-Ject Strobe-it Allignment Disc ( w. alignment of o cartridge.)

Stroboscopic Measure Tool for Turntables very simple very helpfull

The strobeit has two functions

1)  It allows you to check the correct speed of your turntable.( In case you have a Project speedbox SE you can adjust a speed error.)

2) On the back of the strobeit you find a tool to adjust the position of your cartridge in the headshell

Strobe it allows you to evaluate speed variance of your record platter with a stroboscopic hashes. Additionally, on the rear side you’ll find a great cartridge alignment grid that’ll help you position your cartridge optimally in the headshell.

Instructions for Use

Strobe it shows circularly arranged dashes that are assigned to speed and frequency. Please note the ring that matches your desired speed and frequency (60hz inner ring in the US). Put Strobe it on the turntable platter and start the turntable. The tonearm remains in its rest. Align a mains powered light source directly over the turntable with Strobe it rotating. The dashes of the aforementioned ring should now appear still. If they seem to move slightly forward or backward, the speed is either too fast or too slow. Note: use a normal mains-operated light. Daylight, fluorescent lamps as well as flashlights and LEDs (which are DC-operated) are not suitable.