1、The basic use frequency of the handheld radio is 400‑470MHz, most of the power is 5W, the distance of this two way radio in public calls can up to 5‑8 kilometers. Relay device for communicate over long distances. 2、Simple relay, easy to operate and use. 3、No need to change any part of the radio, two handheld radios are needed, connect the cable to the external mic/spk port (2.5mm and 3.5mm). 4、The relay of the two way radio is used to increase the call distance to more than 10KM. 5、K port, use for Kenwood and most brands of radios with the same connector. Condition: 100% brand new Item type: Two‑Way Radio Relay Material: ABS Color: As picture shown Cable length: Approx. 100cm/39.4in Weight: Approx. 95g Connector: K port (for Kenwood and most brands of radios with the same connector) The relay of the two way radio is used to increase the call distance to more than 10KM Two-way communication. Operating mode 1. Transponder downlink forwarding (differential and conventional relay stations), Machine A acts as the upgoing receiver of the signal, and machine B acts as the downstream transmitter of the signal. The relay purpose has been achieved. 2. Two-way forwarding, the machine of the receiver, the machine B transmits. Machine B receives and one machine transmits. Realize two-way forwarding function. 3. The relay box used in the audio trigger mode, when in use, the volume of the two way radio that has received the signal is the largest. Scope of application: 1. Link between relay station and relay station 2. Signal coverage area of relay station signal expansion 3. On-site construction of cable erection 4. Underground mine 5. Cave construction 6. Culvert emergency rescue 7. V-U section relay 8. Small basement and ground two way radio signal connection 9. Emergency use in large events and other occasion 1 x Relay box 1 x Wiring