I use the Roadmaster Even Brake. Bought it used, supposedly only half a dozen times. Works perfectly. No complaints. Fits well in the TJ footwell, and works with brake pedal for either auto or manual trans (pedal for auto trans is wider). Has a function to get rid of any residual vacuum in the system before adjusting itself to brake pedal throw. Like the Blue Ox, which I am sure is just as good, it works on compressed air, which is generated right there in the unit. Runs on the Jeep battery. I added a charge wire so the motorhome charging system is keeping the Jeep battery topped off all the time the MH engine is running. That way, after long days of towing, the Jeep battery is freshly charged and not dying.
2006 Jayco Seneca 34SS
2006 Jeep Wrangler Unlimited Rubicon Toad