Glass Teacup with Infuser and Lid, Glass Tea Mug, Big Tea Cup with Wood Handle for Loose Leaf TeaGlass Teacup with Infuser and Lid, Glass Tea Mug, Big Tea Cup with Wood Handle for Loose Leaf Tea High quality Glass The tea mug is made of high quality extra thick borosilicate glass, which is lead free, and does not contain any heavy metal or toxins. The crystal glass strainer is uniquely designed to reflect the color of your tea. When it is empty, it's transparent with no color. When you are brewing your tea, the edge of the upside shows the color