The DeWalt NA408902 Gear Assembly is a replacement gear component for compatible DeWalt cordless chainsaws, including the DCMCS575N, DCMCS574N and DCMCS575X1 54V XR FLEXVOLT ranges. It forms part of the chain tensioning and drive-side mechanism and is suitable for replacing a worn, damaged or faulty original gear assembly. Compatibility can depend on the machine production date, with later versions using alternative gear part numbers.