Cinegears Wireless Follow Focus
Pricing & availability at B&H
This is an industrial-strength, industrial-priced wireless system. It's robust, smooth, precise, and consistent. It isn't pretty to look at, the hards stops on the controller are fiddly, and I don't like push button programming, but when you're working with geared cine lenses and high-end cameras (and batteries -- the combo gear motor/receiver relies on a cable connected to a PowerTap port like the kind found on the Anton Bauer Cine 150), in my limited experience I haven't seen anything better.