This cable allows you to use the electronics fitted in your Stilo helmet and connecting directly to a Raceceiver unit. The Nexus 4-way plug at one end connects directly into the Stilo helmet comm port, and the 3.5mm jack plug connects into the Receceiver unit. Please note that if you are using a Stilo racing helmet you will also require a set of earplugs (AE0300) to allow you to hear the communications.