This Sennheiser EM 100 G2 wireless receiver operates in the 740 - 776 MHz frequency range. It's important to note that due to this frequency range, it's not legal for use in the U.S. Also, it doesn't come with a power supply or antennas. Before you buy, check your country's wireless frequency laws as some frequency ranges are illegal depending on the country.

Using this Sennheiser EM 100 G2 wireless receiver is simple. First, make sure you've got a suitable power supply as it doesn't come with one. Connect your devices to the receiver as per the standard procedure. Remember, because of its 740 - 776 MHz frequency range, it might not be legal to use in the U.S., so always check your local laws before using it. When it comes to maintenance, keep it in a dry and clean place. Avoid exposing it to extreme temperatures or moisture. If you notice any issues, it's best to consult a professional for repairs.