I don’t recommend it, the device’s power is insufficient. You’d warm the glass faster with your own breath than with this product. It’s fine for warming passengers’ hands, but nothing more.
Affordable, functional solution with the option to replace the battery with a more modern, higher‑capacity one, extending runtime (NiMH 2400 mAh up to about 1 hour).
Works and controls are simple, even for children.
Insufficient info on the shop about the included 700 mAh battery, which is NiCd. Fortunately, it can be replaced with NiMH with much higher capacity, avoiding children’s curiosity about what’s inside a NiCd battery with cadmium’s known downsides (cadmium in the negative electrode is toxic).