Fuser film sleeves compatible with MF645CX, MF641, MF643, MF643CDW, LBP621, LBP623CDW, LBP621CW, 1025, M175, M176, M177, CP1025NW, M251, and 276 models.Designed to support proper fusing function in laser printers by smooth paper passage through the heat roller assembly.Replacement part intended for use during maintenance or repair of printer fusing units.