Used a few times. This is a used item. Compact design U4 wireless in-ear monitor system. - Model: U4 Receiver - Wireless System: In-Ear Monitor - Included: Package, Receiver, Transmitter Operating Frequency Band: 2.4GHz ISM Worldwide Latency: Less than 5ms Number of Channels Usable Simultaneously: 6 Maximum Transmission Distance: Approximately 27m (*Actual transmission distance may vary depending on the environment, such as radio wave reflection, interference, and absorption.) Thank you for viewing. Please refrain from purchasing if you are sensitive to used items.