Great Glass Travel Flask made of Boroscilicate heat resistant glass. Double walled thus insulating your tea and not burning your hands when holding. The lid is removable on its own and you fill with your favourite T BAR loose leaf tea. Put Lid back seal tightly, remove the longer bottom section and fill with hot water, then again screw top section fro the black band back onto the base tightly. Tip the entire bottle upside down and the hot water will enter the top lid section holding the tea. Once you have achieved your desired infusion time again tip the bottle back to its original side, remove the lid from the black band and enjoy your tea.