(Used) 2011 Allison (AT), TRANSMISSION ECM- Trans Model: 3500RDS, ECM Model: A51, Serial Number: BK5536BN1133902A5, Part Number:29545536, Voltage: 12V, Pin Plug: 80 Pins, Rectangular Plug, For more information about this item, give us aa call. We ship worldwide! (CRG HEAVY TRUCK PARTS) 929 W PULASKI HWY, ELKTON, MD 21921