The Neutop Replacement Bristle & Flexible Beater Brush Compatible with iRobot Roomba 600 and 700 Series is a 3-pack of replacement brushes for the Roomba models 614, 618, 630, 635, 640, 645, 650, 652, 655, 660, 665, 670, 671, 675, 680, 690, 692, 694, 695, 760, 770, 780, and 790. According to the FAQ, these brushes will not work with the iRobot i7, but they will fit the 677 and 779 models. However, they may need to be cleaned frequently if used to pick up thick dog hair. The compatibility with other models is also mixed, with the brushes fitting the 500, 675, and 770 series, but NOT fitting the 550 or 890 models. The manufacturer, Neutop Technology, provides customer support through email for any further questions.