After the cable has been delivered, but I was pleasantly surprised that it has 8 wires. That's what I also confirmed my network testers and identified it as a Category 5 UTP. Since the cable is detected even when rolled as properly, it means that the pairs are twisted correctly by T568A / B standard. Another product, also with 8 wires (untwisted) is flunked this test.
Thus, it is capable of gigabit. This also confirms a speed test using iperf. I reach 935 Mbits / s, what the theoretical maximum TCP connections is very close to a gigabit network.
Since I have seen the product only recently, I can not make any statement to the longevity of the retractor.