This cable is also known as the "RPM, Gear Flash, and K Line Cable for EVO4." It has 5 wires to allow connection to an ECU or ignition coil for an RPM signal. The 5-pin "712" (screw-in) connector attaches to the RPM input port on the AiM EVO4. This cable is normally included with the EVO4 unit.
For documentation, please refer to page 23 of the EVO4 user manual.