When I was shopping around for a used truck I test drove one that had a manual exhaust brake. Since then I have not seen one advertised- that is why asked. The truck was a 6spd and the cable ran up the shifter. You just pulled the "tee" with a couple of fingers as it was just under the shifter knob. I have always been kind leery of electronic items as they seem to fail at the worst time for me. A mechanical one just seems simpler,maybe more reliable too.