The Chatterbox Moderate range models are ideal for riders in small to medium size groups of up to 16 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 16 riders (bike to bikes or rider to passenger) at up to 1/2 mile. The XBi2-H Plus features Bluetooth which allows you to pair with up to two accessory devices (cell phone, GPS, mp3/iPOD) at the same time. Each model can also sync to one another for communication. The XBi2-H Plus is designed specifically for the HJC brand line of bluetooth ready helmets. The XBi2-H Plus uses a Lithium Ion rechargeable battery capable of 8-10 hours of talk time with 20 hours standby. The XBi2-H Plus includes the following: Unit, noise suppression Hi-Fidelity headset, factory installed Lithium Ion rechargeable battery, mounting cradle, wall charger and users manual.