Included in this package: (4) ew100 G3 Rack-Mount Receiver (4) ew100 G3 Belt-Pack Transmitter (2) ew100 G3 Handheld Transmitter w/ e835 Mic Capsule All units frequency range: 626-668MHz Headset microphones not included. Antennas not included. Manufacturer Description: With this series, Sennheiser offers high-quality state-of-the-art RF transmission systems with a high level of operational reliability and ease of use. Transmitters and receivers permit wireless transmission with studio-quality sound. Features of the evolution wireless 100 G3 series: • Optimized PLL synthesizer and microprocessor technology • HDX noise reduction system • Pilot tone squelch control • True diversity technology • Switching bandwidth of 42 MHz • Scan function (Easy Setup) for scanning the frequency banks for unused channels