Can not operate the key with the provided software, Windows 8.1. In Windows XP, that's OK, but needs to replace the small antenna provided with a good TV or FM antenna or even an external antenna, if it lacks many stations. With SDR software (I tried several, in particular SDR #), and an external antenna, operation is excellent and the key also works with Windows 8.1. So in SDR, given that it is an 8-bit sample so we can not expect miracles, it's 5 stars, we can not do better with a so cheap hardware. TNT with the supplied software, it is 1 star: as usual Asian software service their equipment, it is impractical and even compatible with the latest versions of Windows, 1 or 2 years after discharge.