The Eaton Fuller Input Shaft, part number 21900, is a genuine Eaton drivetrain component for heavy-duty transmission and transfer case applications. This is a direct OEM replacement input shaft from Eaton’s parts line. If you are cross-referencing this shaft for your specific transmission or transfer case, give us a call at Pro Gear and Transmission and we can help confirm the correct application before you order.Interchanges:HF21900FeaturesGenuine Eaton Fuller input shaftPart number 21900Direct OEM replacement componentSold individually (unit of measure: each)Available from Pro Gear and TransmissionUsed in these Eaton Fuller modelsFS-6005FS-6105