3.5mm mono plug to rca jack adapter 3.5mm mono plug to rca jack adapter is commonly used to convert a rca plug to 3.5mm mono plug.This adapter usually carry's audio or video signals.The adapter is assembled of black molded plastic with nickel-plated contacts.Black molded plastic construction nickel-plated contacts connector 1: 3.5mm mono plug connector 2: rca jack external length / height: 38mm body diameter: 11mm