This package of 350 AeroPress filters should last for months.

The micro-filter removes grit, unlike other press-type coffee makers. These filters are designed for use with the AeroPress, an entirely new way to make coffee. The AeroPress's ideal water temperature and faster brewing yield richer flavor with lower acidity and no bitterness. Water and grounds are mixed together for 10 seconds, then gentle air pressure pushes the mix through the micro-filter in just 20 seconds