It's 4.5 inches in diameter.
I don't have the item, just a photo, so I cant see the reverse side.
I think you're on the right track. It was made to tear off.
Good guess, but Pneumatic tubes were no longer used for US Mail in 1953.
I agree with your assessment.
[IMG] Has Anyone seen such an object before? Any idea what it was used for?
Approved by Post Office Department 10-16-53; TEAR TAB
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