American Hard Bag RCA Rear Channel Adapter for 2014 and Later Harley Davidson Street Glide, Road Glide, Electra Glide Motorcycles Compatible Models: Street Glide, Road Glide, Electra Glide. Will not work with Ultra models. Ultra models require our radio T harness to aquire rear radio signal Plug and play No modification required, no additional adapter required Works with aftermarket amplifiers, only. Does not work with factory amplifiers because it is not a high to low converter Made in the USA and built to last This kit plugs in and converts the included adapter to fit the 4 pin connector that Harley uses for the rear channels on 4 channel bikes. Using this kind of adapter is the simplest and best way to get a signal from your factory Harley radio when installing an aftermarket amplifier.