Thorens Turntable Speed Indicator Accessory


Perusing ebay I noticed this unusual accessory made by Thorens. I like the concept that this speed indicator, made from aluminum, is built to last unlike the cardboard indicators I’ve previously used and possibly it is more precise.

Just one of those curiosity things for me especially as Internet searches resulted in a complete absence of information on this particular device, surprising as Thorens products are so popular. Anybody seen one before? Any guess when these were available, 1950's, early 1960s?
tubes108
I used to have one. It is more durable than a cardboard one and is more likely to be flat. Otherwise, just a strobe disc.

Kal
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Hi Elizabeth. It is reversible, with the "flip side" providing 60 hz! The 2nd photo in the ad shows the 60 hz side of this gizmo. Also it works with 33.3, 45, and 78 rpm records.