I'm in agreement with what the others have said, but you also need to be aware that the tankbag ring will draw power, even with the bike off and run down the battery if you connect it as the instructions indicate, directly to the battery. You have to remove the tank bag to break the circuit. Even if your GPS is off, or completely unplugged from the tank bag power, just the bag on the ring will run the battery flat in a couple of days if it's sitting.
I killed a battery due to this. After that, I wired it to a switched power source via a PC-8 Aux fuse block.
When routing your cable, secure it in such a manner that you still have enough slack to raise the tank fully.
FYI - Many of these seem to get flaky over time and power becomes intermittent while riding. I found this very annoying with the GPS cutting out and having to re-start. Some dielectric grease helped at first, and ensuring that the magnetic plunger was correctly adjusted in as far as possible, but it just got looser over time. Twisted Throttle was outstanding and replaced my upper ring due to a broken pin, but the second one eventually did the same thing, but no broken pin. In the end I ran a dedicated power connection to the GPS and use an SAE plug to remove the bag when I need to. Still enough slack to take it off and place it on the bars for fueling though.
My last conversation with Twisted Throttle discussed the problem and they told me they were waiting to import the new style powered tank bag rings until they saw that they were performing better. Mine was the old style.
For heated gear, use the provided pigtail strait to the battery or to an Aux. fuse block.