Why are there black dots inside the glass-lined handy jug? Is the mercury coming off?

Don’t worry! Those black dots are the supporting points of the glass gall. It’s normal and safe.

Then how should we maintain/protect the glass-lined products?

1. Most importantly, do not hit a hard surface.
2. Although the glass-lined products can keep warm and cold, do not hold hot and cold water within a short interval. Expansion and contraction will break the glass gall easily and lose the hot/cold retention capacity.