Basically, a solid glass bottle. Two disadvantages it has - on the one hand must not be too hot tea, because otherwise the glass is too hot and you can almost not hold the bottle, on the other hand you have to connect the plugs to seal carefully, otherwise runs the mush. But I am very pleased overall with the bottle. The silicone can be removed well, but then does not hold quite as precisely as originally, for perfectionists might be a flaw.
