Cardo Systems Scala Rider Q2 Bike-to-Bike Intercom Communications - New Designed and Engineered for Heavy-Duty Performance Bike-to-Bike intercom communications among up to three bikers within a range* of up to 500 m / 1,640 ft. Rider-to-Passenger communications:Passenger may also conduct mobile phone calls or listen to the FM radio independently. Full Duplex: No longer the walkie-talkie syndrome where one party can only speak when the other is silent. The SCALA RIDER Q2 allows simultaneous speaking and listening between bikers and passengers.