A Two-Way Radio system can consist of two or more portable radios and a stationary base unit. This type of system offers more flexibility and can be carried by the individual because (unlike a CB) the portable units have rechargeable batteries. The different two-way radio brands offer a wide range of capabilities (and prices)—from complex radios with numerous channels to simple ones with a few channels. Their signal range depends on the power of the radio system and the terrain. A license for a specific frequency can be obtained to enable the user to have a private channel of communication.