Cable strain relief to protect the cable - Enables the cable to be bent in a multitude of directions without breaking.
OFC - Oxygen free copper to increase signal quality across the length of the cable.
This cable is commonly used to connect two devices, one with 2 RCA female connection ports and the other with 2 x 6.35mm mono sockets. One of the devices should be an output (mixer/keyboard) and the other would usually be an input (amplifier).
Peace of mind - RoHS Compliant