I have all Cat5e or Cat6 cable are and have times the speed tested with and without this coupling. Unfortunately, the clutch only on paper Cat6 seems to be, because I get the same network with the same cables and the same equipment, only the speed of a Cat5 cable (15-20 MB / s read / write). Without this thing goes up to 50 (reading) and 25 (write). Tested with a 2011er Time Capsule.