HIGO Mini-C 3 pin.
Use this HIGO connector with a light or accessory that you want to plug into the wiring harness of your electric bike. The Super73 S-1 and S-2 use this for the headlight. Note that the system runs on 42v and will burn out a 12 v motorcycle headlamp unless you run it through a converter (in which case, you don't need this part). However, there are a lot of 12v-60V lights out there that you can use.
For the Super73 headlamp connection, order the Female ("F") side and connect it to your light. You can then plug directly into the harness.