Glass Tea Infuser Plunger Brewing SystemThe plunger mechanism is what sets this brewing system apart from a standard infuser. When your tea has reached the strength you prefer, press the plunger to stop the extraction instantly this prevents over steeping, which is the most common reason a cup of tea turns bitter. The result is a consistently smooth, well balanced brew every time, regardless of the tea variety. The borosilicate glass construction lets you watch the tea steep in real time