In the basic version I now own it for some time, and since my wife uses it more often, it's time for a second was time - in this case the with extension, since I anyway for some time a headset looking for that does not have in his ear, but as yet, none have been found with sufficient sound. But there are now.
The advanced features (high, low, play / stop) have been created specifically for Apple devices and thus function well only now complete. Other devices, such as Android smartphones have to be content with the middle PLAY / STOP button. That's a pity, and therefore there is of me a star deduction.
The keys are very small, and very shallow and are very close beinander and are not particularly good for "thick" fingers. In addition, the keys are not particularly sensitive. You have to press vigorously. I let myself be surprised at how long it is going well.
The voice quality of the microphone is good enough to be able to make calls outdoors. However, you should turn away from this wind - but that's for other headsets yes too.
On the whole, the Porta Pro KTC is a sonorous headset that I can recommend with a clear conscience.
