This Tesi Tea Infuser is made of silicone and is perfect for brewing loose leaf tea. It's designed to be easy to use and comes with a string that makes it easy to lift from your cup. Just fill the infuser with your favourite loose leaf tea, then secure it by pressing the top flap. Steep as usual, and when you are ready to remove, use the string or the flat weight on the end. The silicone used in this infuser allows for perfect heat tolerance, making it safe to use in hot or boiling water.