(n.)
Slang.
A rattler is an early-generation PCGS coin holder or “slab”. It is so-called because coins tend to rattle inside them and sometimes rotate in the holder (as with the Morgan dollar in the image above).
PCGS produced three styles of rattler holders, which the company identifies on its website as Generations 1.0 (February 1986), 1.1 (February 1986), and 1.2 (late February 1986-1989)[1].
The rattler holder is made of a thin plastic shell with a gasket to hold the coin and a space on which a perforated insert is mounted. The text on the inserts was printed using a dot matrix printer.
These holders were replaced in September 1989 in favor of a more secure style holder that housed the Doily label.
It is also used to refer to a type of PCGS coin box, which is known as the RATTLER BOX.
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Sources
[1] https://www.pcgs.com/holdermuseum
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