The 2.4GHz high performance digital wireless system with 2 handheld microphones and dual-mode USB receiver. State-of-the-art transmitters and receivers operate in the 2.4GHz frequency band, which is well out of the way of TV stations and cell phone towers, two of the main culprits that wreak havoc in the wireless zone and because it is digitally encrypted, signal gets through in all its pristine, high-definition quality, without the random artifacts that often plague other wireless systems. Replacing batteries in wireless MICs can get expensive really fast and having them die in the middle of set can be a showstopper. Ensuring that battery life is extended as long as possible. Operating in the 2.4GHz band allows Behringer ULM series USB wireless microphone systems to be used across the globe without any special licensing requirements.