The OBD socket is a 12-point plug that is generally under, or near the steering wheel. It is predominantly used by mechanics to gain access to your car's onboard computer. This allows them to read specific engine and operational levels of key components in your car.
KOBA's Rider device plugs directly into that socket and transmits data continuously (while the car is on) to ensure we have an accurate reading on the location and duration you are driving so we can accurately charge you for what you use.