This is a I2C cable suitable for use with the 16n. It has a 3.5mm TRS connector on one end and standard square post connectors on the wires on the other.
Standard I2C pinout is Tip=SCA, Ring=SCL, Sleeve= GND
The wires are color coded:
White = Tip/SCA
Red = Ring/SCL
Yellow = Sleeve/GND