Data jack is an easy to assemble compact adapter used to converter EIA interfaces using standard D-sub (9, 15, 25 position) connectors to standard monaural 4, 6, 8 contact (RJ11,12, or 45) jack, data jacks are available as kits or assembled to your specification. Data jack also can be used to allow an EIA RS-232 computer system to run over a UTP wiring system.