LiftMaster 8-foot replacement belt assembly, part number 41A35891. One-piece design for 8-foot residential doors. This belt is also compatible with some 7-foot LiftMaster and Chamberlain operators made before 2001 when used in the correct setup. When your belt is frayed, has missing teeth, or the opener is skipping during travel, this fixes it. Note that This replacement part is not the same as part number 41A543413, which is for newer 8-foot belt-drive units. Older openers use a different belt profile. Check your opener's model and manufacture date to pick the right one.