This is another idea of the thermochromatic banger. As yellow boro glass gets hot, it will change color. The idea behind this is at a certain color the banger is the proper temp. Once you figure this out you can get a nice hit. We feel just a cold start dab is way better as you get the coolest hit. Even better is getting a Silver Surfer with the quartz dab dish. This allows you to find your perfect temperature and then the Surfer will maintain the temperature for you. This gives you the perfect hit every time.
Learn more about different bangers here