star sapphire washer on spindle?

what is the deal with this washer?  i’ve had a sapphire and star sapphire, both came with this washer.  it appears too thick to allow the record to clamp or vac flat against the platter.... don’t get it.

both these tables are mid-80’s tables. with reflex clamp.  have searched and can’t seem to find any info.

Washer sits under the record when you use the reflex clamp. If it is too thick, then either someone has put the wrong washer on or your reflex clamp is not working properly. There is a screw inside the reflex clamp for adjustment.

what's the correct thinkness?

one i have on both tables is rubber and ~.095" (or 2.4mm) thick.
the notch on the platter is only .010" (0.25mm) deep.

so the reflex clamp is suppose to compress this rubber washer .085"?

The washer keeps the center of the record (the label) up just a bit, so when you use the clamp, the edge of the record flattens out against the platter.

On the SOTA tables, you only use it if you have the reflex clamp.

VPI, Oracle and several others use this same approach.
I found that the washer that came with my VPI useless. When I used it with a clamp,the record would never flatten out against the platter. As a matter of fact most of the time I don't even bother using the clamp!