Dual Head Toy Heating Stick LED Indicator Light Heating Meat Stick USB Hand Warmer 42℃ Automatic Control Fast Heating Portable Carrying Outdoor Heating Tea/Coffee/Water, 2 Heaters Combined into 1 Cord

As the headline stated, these are perfect for warming your doll(s) before use.I cannot give them five stars because the USB cord length is ridiculously short. You may want to buy a USB Cable extender. Otherwise, this would be a 5-star product.

This works decently for a USB heater. It does not heat up as fast as the corkscrew metal electric immersion heater that I have but it does eventually heat up the liquid. It works best with a taller mug as the top gets much hotter than the bottom of the unit. As to be expected, this requires a lot of power and only worked for me when plugged into my wall outlet, my laptop port, and with newer, beefier power banks. I tried with an older power bank that I often take camping and it would not power it. I think this will work out great at outdoor events to keep beverages warm when it's cold. It works best to maintain an already hot beverage but will heat cold liquid if given enough time. The instructions appear to be incorrect as it states that the alternating red and green light means it has reached temp. For my unit, it displayed alternating red and green lights from the moment I plugged it in. In any case, I think it's a decent value for the price and a handy gadget to have.

Doesn’t work ! Don’t waste your money

Got these for some toys and they worked really well. They heat up pretty quickly and fit in tight spaces. Only thing I didn’t like about it is they don’t have an on and off switch or any temp control so it’s just on and one heat setting. They don’t get super hot to where you can’t grab them or melt silicone.