A telephone available for public use and requiring that the customer pay for that use by inserting money, usually in the form of coins or a debit card or credit card of some sort. Pay telephones traditionally have been provided by the local telephone company, although deregulation allows other parties to provide them in the United States and some other countries. A customer-owned coin-operated telephone (COCOT) is owned by the end user that owns or occupies the premises in which it is located. A payphone service provider (PSP) is a third party that may own a great many payphones. The pay telephone was invented by William Gray, who installed it in a bank in Hartford, Connecticut, in the United States. Gray previously had invented the chest protector for use in the game of baseball. A pay telephone is no longer a common sight in North America and many developed regions of the world, as the low cost and wide availability of cellular telephones have made pay phones unprofitable. Synonymous with payphone and pay station.