Registered jack specifications are related to the wiring patterns of the jacks, rather than their physical characteristics. The term RJ45 has also come to refer to a range of connectors for Ethernet jacks. An 8 Position/8 Contact connector, called an 8P8C, is a modular connector for telecommunication cables. It is also informally referred to as an RJ45.
Modular Plug RJ45 8P8C