A diffuser is a small metal cage-like ball in which you put the loose tea leaves. It acts like a tea bag where you put it inside the kettle and the hot water flows through the diffuser and is infused with tea.
Does that make sense?
There are some on this
website (called infusers) in the gifts section.
You can't beat fresh tea...yuuuummmy!!!
Don't know where you are so don't know where to direct you to buy one.