This is a great LITTLE device I wish I had known about sooner. Basically a battery powered remote control for running jacket and something else (gloves in my case) independently.

It replaces my Gerbings dual controller that is not remote and therefore hard to access while riding. Gerbings knobs are also floppy and twitchy to adjust. By comparison the remote Heat Troller is tiny, clearly marked and simply velcroed under the shelf holding my radar detector. Easy to use and very portable to another bike. I'd suggest buying one of the remote Heat Trollers before considering either of the Gerbings controllers.

The receiver unit that plugs into the jacket (the Heat Troller is plug compatible with Gerbings coax plugs and most other brands of heated gear) is very small and light, a useful improvement also compared to relatively clunky Chinese stuff sold by others.

See and look at Gen4 products to see the item.

Note also the Gen 4 jacket - a bit more expensive but more flexible item than the a Gerbings design. I find myself wearing an Aerostich windproof fleece jacket (ONLY) at temps down to 55 or so so have interest in a heated windproof fleece jacket that might extend comfort to 45 or so without any other jacket layer. Anyone have experience with the Gen 4 jacket?