They work well and keep your hands relatively warm. Kind of expensive but heck it's worth it to not freeze your fingers off trying to make a phone call or play a short game while you wait outside in a line.
But sadly nothing more. I thought I could use this to charge and do a data transfer but no. It's just a charging device. It does charge devices that utilize this port but you can't use it to transfer data also.
The only thing I would improve on it is adding bluetooth compatibility. I hate that a USB slot is taken on a mobile device. Otherwise it's a great product and would DEFINITELY recommend it to anyone who has a laptop and hates trackpads with a burning undying passion like I.