Small size, compact structure.
No wires or batteries (adapter is powered by the diagnosis size sockets).
Stop communication, wait half an hour, auto sleep.
It uses AT commands to communicate with a host device (PC, notebook, iPhone, iPod touch, iPad and so on).
Some of them have pretty useful features, such as engine running parameters monitoring, DTC reading and clearing, MPG meter, etc.
It also comes included with a power switch built-in to prevent the need for having to constantly disconnect your unit from the OBDII port.
Display current sensor data, including: vehicle speed, RPM, fuel consumption, engine coolant temp, fuel pressure, calculated engine load, throttle position, intake manifold pressure, air intake temp, timing advance, mass air flow, fuel level, barometric pressure, EVAP system vapor pressure, fuel trim.
Clear trouble codes and turn off the MIL (Check Engine light).
Read diagnostic trouble codes, both generic and manufacturer-specific, and display their meaning.
ISO 11898(aka. CAN)
ISO 14230(aka. KWP2000)
ISO 15765(aka. CAN)