LiftMaster 041C4220A Gear and Sprocket Kit Assembly has a 1 piece

Assembly has a 1 piece belt with the bullet attached

045ACTMC is a 315MHz Security+ 2

Item                                       Commercial Door Operator

you can expect that the other one will break very soon

LiftMaster 041C4220A Gear and Sprocket Kit Assembly has a 1 piece041C4220A is a complete chain drive gear and sprocket replacement kit. This gear and sprocket assembly is compatible with various chain drive garage door openers; manufactured after 1993. Complete kit includes: Helical gear and top hat assembly, worm gear, wear bushings, grease, and hardware needed to replace the chain drive gears. Check the manual or replacement parts diagram for specific part information before ordering to ensure compatibility. Also