The Chatterbox Moderate range XBi2 models are ideal for riders in smaller groups of up to 3 people. They feature CDMA technology for communication, which allows them to be much smaller in size. This technology allows full duplex (conference call type) conversations between a max of 3 riders (bike to bike or rider to passenger) at up to 500 yards. Both the XBi2 and XBi2-H feature Bluetooth which allows you to pair with up to two accessory devices (cell phone, GPS, mp3/iPOD) at the same time.