Okay for the price, but frequencies unclear

For the reasonable price, the quality is fine. An audible noise is unfortunately doing that can be censored. The coverage is fine, for an interview on camera (no more than 10m distance) extends the performance.
The operation is very simple (batteries in, turn on), a pity that is not exactly clear what use the frequency range devices. For professional events I would therefore devices - alone apart from the quality - not allowed because it is not clear whether the frequencies will only be accepted. For short hobby projects use is still justifiable.