Symtec heat demon part number 210019RR for the elements and part number 210008 for the thumb warmer. Both are 3 wire setups. One for high and one for low. (You could use the high/low elements with a controller if you wire the high side only.)
I used to tie them into one switch but now I use 2 so I can control the thumb separate from the grips. I use mitts in the cold weather and Klim gloves so I only need the warmers on the really cold days. I also don't use the cheap plastic switch. I use a metal toggle switch and the rubber waterproof cover.
I think BrianE uses the elements under his ODI Grips. That's what I will be going to next time since I had to glue my grips on to prevent them from slipping. If I'm careful, I hope to be able to cut them off when they wear out???
This year we are snow biking mostly. I hope to not need them on the bike, but I have the ODI lock on grips so I can add them if I need to.
Dobeck AFR+, Hayden fan controller, QSC Rev-X primary/STM secondary, TORQ Locker
26x9 Kenda Bearclaw HTR on No Limit Octane custom wheels
Powermadd hand guards, RotopaX 4 gallon, Symtec heated grips, Homemade UHMW skid
Tatou 4S tracks with SpeedoHealer and Klim winter gear
My YouTube page
(mostly unedited track rides)