Vehicle tracking devices can vary a lot in their appearance, and depending on their purpose, can even be home made.
However, a typical commercial device will look like a small, black box, constructed of plastic and small enough to hold in one hand. Some will have an antenna to allow connection to a satellite signal, but these can be built internally. Connection ports also vary, and can come in the form of one or more wires protruding from the side of the box, or a socket which allows the box itself to be connected to the car.
Most devices work by connecting to a vehicle's On Board Diagnostics board (OBD) which can be found near the driver's seat, often either under the dashboard or under the floor of the driver's foot-well.
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