The radio relay is GMRS frequency; please tell us before if you need customized frequency version ^^ Upgraded feeder cable; which can reduce 1-2W power loss; the new cable's size is 10.62 mm; much larger than the previous 4.88 mm ^^ The RT97 GMRS base station repeater is easy to carry and support multiple power options; wide signal coverage and strong penetration; easy to install and operate; mobile base station can be operated flexibly as fixed or mobile ^^ The built-in duplexer can receive and transmit signals at the same time; you just need to match one antenna to transfer the signal of the walkie talkies; this package does not include an antenna ^^ With 16 channels; 8 of them are default GMRS channels that have been set; it can compatible with NR30S; RB48P; RT76P; RB26 and many other retevis models