Just back from a tarmac ride to test the Klan heated jacket kindly loaned to me by Andy (Shack).
Andy's vest uses a cigarette lighter plug which was ideal as I have one on the TTR bars to fuel my GPS.
Very very toasty - lovely bit of kit. Might take a bit of thinking on the cables but for those trail rides where you have to travel a little way to the start, and maybe back home in wet or cold, the vest is ideal.
The warmest part of the vest seems to be over your kidneys which is good thinking!
I was also loaned a matching pair of gloves which attach to wires in the sleeve of the vest. I have large hands but the gloves fitted fine and are like gauntlets and fit nicely over my riding jacket sleeves. Sadly, as I was warned, they had faulty connections or summat and they didn’t heat up but I got the idea and might be a good alternative to heated grips. They aren’t as bulky as winter gloves so wouldn’t be a problem in that way.