Use your own gourmet ground coffee in a Keurig brewer--Just fill the Reuseable filter with your favorite coffee and pop it into your brewer.....Just like a regular K cup K-cup Single Reusable Coffee Filter for Keurig B40, B41, B44, B45, B50, B60, B65, B70, B75, B77, B79, K10, K40, K45, K60, K65, K70, K75, K77, K79 - 6 Pack 100% BPA free No need to remove or swap out the filter holder; Built-in permanent stainless steel micro mesh filter Works in Keurig B31, B40, B44, B60, B50, B66, B70, B77, B200, B140, B145, Breville Kcup, Mr. Coffee Kcup , Cuisinart Kcup They are NOT compatible with KEURIG B30 - B130 - B150 - B 155Goldenvalueable