A JACK PLUG SOCKET

A jack plug socket comprises a housing (1), a plurality of jack plug contact pieces (11, 13, 15) and a plurality of switches. The contact pieces (11, 13, 15) contact a jack plug (P) when the jack plug (P) is fully inserted into the socket and the switches are adapted to be operated by the insertion of a jack plug (P) into the socket. The jack plug socket also has a cover (31) formed of an electrically insulating material and which is removably attached to the housing (1). The terminals (11d, 15c,) of the contact pieces (11, 13, 15) and switches pass through the cover (31) at positions spaced apart from the housing (1). A supplementary switch (30) which is adapted to be operated by movement of at least one of the contact pieces (15) resulting from insertion of jack plug (P) into the socket is supported by the cover (32). The cover (32) and associated supplementary switch (30) can readily be removed and replaced by a cover which does not have an associated supplementary switch. Reduced manufacturing costs and versatility of application can be achieved.