[jmrm]

I find incredible a product like this is in the market, where the minimal price to pay for a similar professional device is around $4000, maybe a couple thousands for lower end models.

Of course the accuracy of this device might be a lot less than those professional devices, but when you are a ham amateur hobbyist who want to know if some transceiver, antenna, cables, or other devices are working good, you get a lot of "device" for such a low price.