2021 Allison 2500PTS, School Bus, Transmission ECMs, Fits to: Freightliner B2, (Used) 2020 Allison (AT), TRANSMISSION ECM- ECM Model: A61, Part Number: 29556882, Serial Number: BK6882A100315528, Transmission information- Model: 2500PTS, Serial Number: 6311834955, Plug Pins: 80 Pins Plug Rectangular, Reference images for condition. For more information about this item, give us a call. We ship Worldwide! (CRG HEAVY TRUCK PARTS) 929 W PULASKI HWY, ELKTON, MD 21921, Serial# BK6882A100315528, Casting# BK6882A100315528, Truck Year 2021 4UZABRFB0MCMK5861