The tea pot relies on a plunger system in the stainless steel filter that can be pushed down to stop the brewing process. The plunger has a rubber gasket (ring) around it that seals the tea leaves in the bottom inch of the strainer. I take the rubber gasket off to wash after each use.Unfortunately the gasket was thrown away by mistake so I called the company to order a new one. I had to leave a message since the computer does not have any live customer service. Actually I left several messages and emails to no avail. If I wanted a new gasket, I would have to buy a whole new tea pot. In the end it made no difference because the glass tea pot cracked in the dishwasher shortly afterward.I have since purchased the FORLIFE Brew-in-Mug Extra-Fine Tea Infuser with Lid on Amazon and been very happy with it. I gave several away as Christmas gifts too and they were well received.