You are buying quality paper XEROX copy from UNIQUE strobe turntable disk for ALL FOUR turntable speeds:

16&2/3, 33&1/3, 45, 78 RPM.

 For each speed this disk has FIVE (5) sets of marks and give you opportunity  set disk speed 16, 45, 33 or 78 RPM with accuracy  +/-2% or +/-4%.