RJ45S Jack
Now obsolete, RJ45S was an RJ standard for connecting a single data line, utilising a keyed 8P8C connector and a programming resistor. RJ45 is often mistakenly used to refer to the 8P8C Ethernet connectors covered by the TIA-568-D.2 standard. Ethernet utilises un-keyed connectors and physically incompatible with RJ45C connectors, which are keyed.