Designed for use with the Aeropress Coffee and Espresso Maker, the paper microfilters prevent grounds from entering your cup, unlike with French press coffee brewers. The AeroPress coffee and expresso maker is a new kind of coffee press that uses a rapid, total immersion brewing process to make smooth, delicious, full flavoured coffee without bitterness and with very low acidity. Micro filtered coffee and espresso so pure and particle-free that it can be stored for days in a refrigerator as a concentrate and later made into delicious American coffee! For use with Aeropress coffee and espresso makers only.350 count pack. Measure: 2 1/5" diameter.