Cables designed to transfer signals between smartphones and audio devices such as headphones and microphones. Terminated with 3.5mm mini jack connectors, smartphone cables will either have a TRS or TRRS style connector, with the TRRS having an extra black insulation ring on the connector. A TRRS cable has an extra conductor/wire inside the cable, and is capable of carrying both Left/Right audio signals, as well as a microphone signal. The rise of the headset (mic and headphones) for use with smartphones, saw the rapid rise of the TRRS connector and is now the standard 3.5mm audio plug for laptops.