It does the job, the positive thing is that if both are connected, one of them has a beeper. So instead of waiting every time to press the test, you know when you have found the correct cable. It does a basic certification of the conductors and finds the length of the cable with decent accuracy. It does not certify the speed, of course, but if we have used the correct cat6 cable, the contacts are terminated correctly (the machine shows this) and we have not exceeded 100m, then there is no reason to question the result.

P.S. Not even for serious professional use.