Racing Radios 4 Conductor IMSA coil cord radio helmet kit. Used mostly in sports car racing, IMSA, Grand-Am, SCCA, etc. It allows the driver to have some movement with the helmet with the coiled cable. The Kit comes with a 3.5mm earpiece connection and top of the line noise-canceling microphone. *comes with installation instructions and mounting hardware for Non-Drill and Drill methods.