This Sennheiser SR 300 IEM wireless transmitter operates in the 630 - 662 MHz frequency range. But note, it doesn't come with a power supply. Due to the frequency range, it's not legally usable in the U.S. Before buying, check your country's wireless frequency rules. Some countries ban using certain frequency ranges. It comes with an antenna, which helps improve signal reception.

Using this Sennheiser SR 300 IEM wireless transmitter is simple. First, make sure you have a suitable power supply as it's not included. Connect the antenna to enhance the signal. Then, set it to the right frequency within the 630 - 662 MHz range. Remember to check your country's laws on wireless frequencies before using it. To keep it in good condition, store it in a dry and cool place. Avoid exposing it to extreme temperatures or moisture. Clean the antenna and the device regularly with a soft, dry cloth.