The AiM EVO4 Data Logger is designed to use GPS for the speed signal, but it also has two channels for wheel speed. To keep the physical size of the EVO4 as small as possible, only one input port is provided on the unit.
This special splitter (Y-cable) is required to connect two wheel speed sensors to the single Speed input port. The male (logger) end is a 4-pin* 712-type (screw-in) connector. The two female ends each have 719 (push-on) connectors to accept either the AiM Magnetic Wheel Speed Sensor (Part No. MC-216) or the AiM Wheel Speed Proximity Sensor (Part No. MC-217).
* AiM wheel speed sensors normally use only pins 1, 2, and 3. This special cable uses pin 4 for the second speed signal. This pin is not read by any other AiM logger or dash.