If you're like me and run Tunze powerheads in your tank and also have a Neptune apex you need these cables. Plain and simple. There are no alternatives.
But here's a heads up for anyone using these cable with pre-2015 models of Tunze controllable powerheads. The male serial connector on the cable doesn't quite fit the female serial connector on the power head. Thus it won't stay connected and slides out quite easily.
The solution is to take a razor and remove about 1mm of the black shielding on the cable. This easy and procedure will guarantee a strong connection between the cable and the powerhead.
NOTE: You will not need to perform this procedure with the newer 2015+ models of Tunze powerheads with the built-in controller. They fit fine in those. It's just the pre-2015 without the controller.
