Retevis RT-B6 Walkie Talkie Handheld Transceiver VHF/UHF 136-174/ 400-480MHz 99CH DCS/CTCSS DTMF FM with Original Earpiece (5 Pack) Frequency Range: 400-470MHz/136-174MHz; 99 channel; 104-DCS, 50-CTCSS Better antenna: inductivelyloadedantenna; Stubborn and boost the radio distance Emergency Alarm: When the user is in danger situation, press the Emergency Alarm button to call for help: should program to set up PTT-ID function could let you know who are speaking to you; VOX function for true hands-free communication Range up to 3.5 miles (6 km) depending on environment and terrain