12V plug-in boot heaters?

I’m sure I read about an insole for snowmobile boots or biker boots that has quick disco leads that can be plugged into a snowmobile 12v socket, or a bike, or ATV…and in my case, into my boat socket. Trouble is….I can’t find what I’m looking for. My local Ski-Doo dealer says he doesn’t have them…and I’ve googled the net w/o success. Anybody have a lead for me? Thank you if you do… After fishing in my new Frabil Snosuit last week, the last part of me that got cold was feet…

http://www.gerbing.com/Products/insoles.html

I am also considering upgrading my current electric socks to something similar to these insoles.

The 8 AH lithium battery sold with these insoles is $189 and only weighs 1.3 lbs. It also comes with a temperature controller and should power the insoles for 6.6 continuous hours at the highest temperature.

If I go with these, or similar insoles, then I will probably test them out by connecting them to one of the boat batteries first, then buying an AGM sealed battery when not fishing in my boat.

This 12 volt AGM 7.5 AH battery (5.8 lbs) for $29 looks like a good match http://www.batteriesplus.com/pc-32634-32634-WKA12-7.5F.aspx

Thank you Jon and Dave, I’m off and running with your leads.