Ni-Cd stands for Nickle-Cadmium. Ni-Cd batteries provide considerable power, and have consistent discharge rates allowing the tools they power to perform consistently throughout the charge cycle.
This is an authentic manufacturer-sourced replacement part which is specially made for Hitachi power tools. It helps to secure a carbon brush in the housing. Please make sure to refer to the appropriate diagrams of your model for the correct location and application of this hardware. Keep in mind this high-quality item is made of durable plastic and is sold individually.