<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (September 2014) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (September 2014) (Learn how and when to remove this template message) </Td> </Tr> <P> A 45 rpm adapter (also 45 rpm record insert, 45 rpm spindle adapter, or 7 inch adapter, the common size of 45 RPM records) is a small plastic or metal insert that goes in the middle of a 45 - rpm record so it can be played on the LP or 78 rpm size spindle of a turntable . The adapter could be a small solid circle that fits onto the bottom of the spindle (meaning only one 45 could be played at a time) or a larger adapter that fits over the entire spindle, permitting a stack of 45s to be played . </P> <P> The first 45 rpm inserts were introduced by the Webster - Chicago Corporation, also known as Webcor . They were made of solid zinc, difficult to insert into a record and almost impossible to remove without breaking the disc . A differently shaped, but similarly difficult - to - use metal adapter was made by Fidelitone . Capitol Records for a time produced what they called "Optional Center" or "O.C. 45" records . These had a triangular cardboard insert with an LP - size spindle hole; the cardboard center could be punched out for playing on 45 rpm spindles, but could not be replaced . </P>

What is the name of the plastic insert on a 45 record