Answer a question about this article:
RCA 45s were also adapted to the smaller spindle of an LP player with a plastic snap-in insert known as a "spider". These inserts, commissioned by RCA president David Sarnoff and invented by Thomas Hutchison, were prevalent starting in the 1960s, selling in the tens of millions per year during the 45 rpm heyday. In countries outside the U.S., 45s often had the smaller album-sized holes, e.g., Australia and New Zealand, or as in the United Kingdom, especially before the 1970s, the disc had a small hole within a circular central section held only by three or four lands so that it could be easily punched out if desired (typically for use in jukeboxes).
How many spiders were sold in the 45 rpm heydays?
tens of millions per year