Nitrous Bottle Warmer
We use a warmer blanket and a milwaukee 12v battery on our race car and we can have a bottle up to temp in the lanes in a matter of minutes
The heater is the cheap Dracary $75 from Amazon and it works surprisingly well. The bottles are mounted in the bed of my truck out of direct sunlight hidden under a Bakflip Tonneau cover. Summertime the bottles heat up fast and the transducer cycles very little... and of coarse with colder weather it takes a bit longer.

They are convenient and look nice, but don't do as good of job.
https://www.ebay.com/itm/173953234509










