The Sennheiser EM 100 G2 Wireless Receiver operates in the B frequency range of 626 - 662 MHz. Note that due to the frequency range, it's not legal for use in the U.S. Always check your country's wireless frequency laws before buying. Remember, this unit doesn't come with antennas but includes the correct power supply.

Using the Sennheiser EM 100 G2 Wireless Receiver is straightforward. First, connect it to the correct power supply that comes with it. You'll need to provide your own antennas as they're not included. Before you start using it, make sure to check your country's wireless frequency laws because some frequency ranges, like the 626 - 662 MHz range of this receiver, may be illegal in certain countries. When it comes to maintenance, keep it in a clean and dry place. Avoid exposing it to extreme temperatures or humidity. If there are any issues, refer to the manufacturer's instructions or contact customer support.