The knob on the lid is made of plastic, which prevents scalding when the lid is removed. The lid and strainer are made of 18/8 stainless steel, which ensures that no rust occurs. Healthy, crystal-clear borosilicate glass withstands temperature fluctuations from minus 30 °C to plus 150 °C. It stays intact even if you pour boiling water into a frozen pitcher. So the teapot is healthy and durable enough to be used.
Borosilicate glass is known for its low thermal expansion and high thermal resistance. It can be used on gas, electric cooktop (not induction cooktop) cookers and many others.
Make sure there is no residue in your tea. The strainer can be removed if you don't want the tea to steep for too long. Without the strainer, the lid can still cover the pot.