Cardo Scala Rider Q2 MultiSet PRO Intercom Helmet Communication system Bike-to-bike intercom - alternate between 2 other riders within a range of 700m/2,300 feet Rider-to-passenger communications - both rider and passenger usingQ2PRO headsetscan communicate via intercom as well as independently conduct mobile phone calls, listen to MP3 music in stereo or to the built-in FM radio Full duplex - no longer the walkie-talkie syndrome where one party can only speak when the other is silent; theScala Rider Q2PROallows bikers and passengers to talk and listen simultaneously Talk time is up to 8 hours Standby time is 7 days