Licence Free UHF/FM Radio with up to 5Km range, 8 Channels and communicates with all other 446 Radios Provides an easily recognisable call alert for incoming calls Roger Beep confirmation tone that indicates to others when it is clear to talk A unique circuit extends the life of your batteries. If there are no transmissions within 10 seconds, the unit will automatically switch to battery saver mode Micro-USB chargeable. Rechargeable batteries can be charged inside the radio