"Burton pre-wired the Imprint 5 liner for Therm-ic heat packs" If you are considering buying these boots just for their heating elements, don't bother (in my opinion). You have to spend MORE money to get the battery packs and the charging units! The battery packs weight a fair bit too and can end up flying about if they slip loose. Therm-ic do a Lithium battery pack which is much lighter and lasts much longer in the cold... but guess what, you have to spend MORE money, an extra $100 for those! And then, after a hard days shred you forget to put the buggers on to charge over night... it's back to the stick on toe warmers :(
In my opinion, don't buy these boots just because of the option to use Therm-ic heat packs.. buy them because they fit ya like a glove and keep ya riding sweet all day!