Photographer's Formulary Reducer IV for Negatives is similar to Ansco 311. It is not a true reducer; rather it is only bleach.
Reducer IV converts the silver metal in the negative back to a silver halide, which then can be reconverted to silver metal in a redevelopment step. Any standard developer can be used for the redevelopment.
The chemicals in this kit are used to prepare 1 liter of working solution, which is reusable. The working solution keeps well and has a high capacity.