Specification: Distance: 5-8 km from open space, 1-2 km from densely populated buildings Line length: Both sides are 90cm/35.4in long (Left and right) Package list: 1 * Relay Box Working Mode: 1. Different frequency uplink and downlink difference forwarding. A machine as the signal uplink receiver, and B machine as the signal downlink transmitter. The relay has been achieved. 2. Two-way forwarding, when the A machine receiver, the B machine transmits. When the B machine receives, the A machine launches. The two-way forwarding function is achieved. 3. This relay box is an audio trigger mode. When using it, the volume of the intercom as a receiving signal should be adjusted to the maximum! Single/two-way relay box frequency setting prompt. 4. One-way relay box forwarding mode.The A machine receives the signal and the B machine transmits the signal. The receiving/transmitting machine must be set to two different frequencies. The frequency set by the conventional transmitter is higher than the receiver frequency, and the high/low frequency is low. The high/low frequency difference is generally 10M, and the larger the frequency difference, the better. 5. Do not reverse the jack of the one-way relay box during use, otherwise the relay box will not work. Notes: 1. This relay box is an audio trigger mode, so please adjust the volume of your walkie-talkie to the maximum when using it, otherwise there may be no forwarding status. 2. If the transmission delay time is too long (more than 3 seconds), the transmitter's transmitting antenna is too close to the relay box.