No more mess in your cup! The Perma-Brew tea infusers provide all the economy, flavor and variety available from loose unbagged tea without the mess of loose tea leaves in the cup or pot. These refillable tea bags are simple and easy to use: simply fill with tea leaves, drop into your cup, and steep until the tea is finished brewing! Constructed of polyester filter mesh with integrally molded plastic frames, the tea infusers avoid imparting any metallic taste to the brewing tea, which is a common problem with metal tea infusers. Their fine filter media, with openings just 225 microns in diameter (1 micron=0.000039 inches) are far smaller than the stamped holes in metal infusers, keeping all of the tea leaf mess inside the infuser and out of the cup! Less for you to worry about, so you can relax and enjoy your cup.